This article is part of our MMA Barometer series.

Once again a main event is derailed in the 48 hours before the fight. Late Thursday night Ariel Helwani of MMAFighting.com reported that Ray Borg was withdrawing from his UFC flyweight championship fight with Demetrious "Mighty Mouse" Johnson. This news ruins Johnson's chances of extending his consecutive title defenses to 11 to break his tie for most consecutive title defenses with Anderson Silva. Borg apparently has a viral infection, and his illness was not related to cutting weight. This is the second time in three pay-per-view events that the main event has been scratched just hours before the event takes place. Ironically, the replacement main event for Johnson and Borg will be Amanda Nunes and Valentina Shevchenko for the UFC Women's Bantamweight Title. That fight is the last main event to be cancelled because of illness, less than 24 hours before UFC 213 took place. The news concerning Borg comes on the heels of a positive test for diuretics by Junior dos Santos, which took one of the most anticipated fights off of the UFC 215 card between "Cigano" and Francis Ngannou. Thankfully UFC 215 had two title fights scheduled, and there are other exciting fights to fill out the card.

The loss of the Johnson fight leaves those with DraftKings lineups left to scramble for a replacement with $9,600 in available salary to do so. Most lineups will now leave money on the table, as Johnson was the highest-priced fighter. The next biggest favorites are Henry Cejudo ($9,100), Adriano Martins ($9,000) and Sara McMann ($8,900). Personally, I think McMann is the safest bet to win, though Martins (versus a Tristar product in Kajan Johnson) is the biggest betting favorite remaining at roughly (-500). Making this decision correctly could make or break lineups, as we had anticipated Johnson would have incredibly high usage Saturday night. The champion has a high work rate where he lands a lot of strikes (3.49 per minute), and he has also finished four of his last six fights. Fortunately, there are other action-packed fights that can contribute to point totals. In particular, Jeremy Stephens and Gilbert Melendez has a potential to be Fight of the Night. Both fighters are no strangers to brawls, and this has a great chance to be a slugfest that doesn't make it to the judges. Additionally, Ilir Latifi and Tyson Pedro are both quite familiar with first-round finishes. Pedro has finished all six of his professional fights and five of Latifi's eight UFC fights have ended in the first round.

Even though it is disappointing that the main event was cancelled less than 48 hours before it was scheduled to take place, the depth of this fight card should be sufficient to make it an exciting event.

As always, below is your MMA barometer with rising, falling, and check status fighters.

Rising

The Russian heavyweight is fresh off of a great performance against Stefan "Skyscraper" Struve. Volkov found himself in trouble early as he had a huge gash opened under his left eye from a Struve knee in the first round, but he recovered well. At 6-foot-7 he is a very long fighter and uses his length well while striking. Struve's reach advantage was not a problem for Volkov, as he out-struck the Dutch fighter 135-41. Volkov had a good work rate throughout the fight, and although both fighters seemed to be tiring in the third round, he was able to get the TKO victory with a flurry of strikes. Volkov also showcased an impressive ground game as he was able to capitalize on two takedowns and land good ground-and-pound against Struve, who is notoriously tricky with his submissions. Struve may be a lesser fighter than he was a few years ago, but a TKO victory is nonetheless impressive against the now No. 10-ranked UFC heavyweight in the UFC.

In his next fight "Drago" will look to square off with a top of the food chain UFC heavyweight. At this point, it seems that most of the top of the division are tied up in other matchups. Alistair Overeem will likely fight Francis Ngannou, Fabricio Werdum is set to face Derrick Lewis, Mark Hunt will fight Marcin Tybura and Cain Velasquez is still injured. Junior dos Santos would have been a great test, but his recent positive test for diuretics will put him on the shelf for a minimum of six months. A good test for his next fight would be the winner of no. 5-ranked UFC heavyweight Hunt and Tybura. Hunt will likely be a heavy favorite in his fight with Tybura, and a fight with him would show where Volkov stands in the division. "Drago" would have a good chance to come out victorious in that fight, as his length would cause problems for Hunt, who is a very short heavyweight. Even though his length would be an advantage, it would be dangerous to stand toe-to-toe with one of the most decorated strikers in the division in Hunt. Volkov could use his size and purple belt in Brazilian Jiu Jitsu to wear down Hunt. If Volkov was able to get past Hunt, or any other fighter near the top of the division, he may be a good choice to challenge for the title. Volkov has championship experience as the former Bellator heavyweight champion and former M-1 Global heavyweight champion, and would have the endurance to survive a five-round fight.

Next Fight: TBA

Darren Till, UFC, Welterweight

Till looked impressive in his latest fight with Bojan Velickovic. Till brings an exciting style to the Octagon with great Muay Thai skills and a brash attitude. He is extremely confident, as he showboats during fights and is quick to claim he is the best welterweight in the world. So far, he has backed that up in the UFC with three victories and one draw. One of the English-born fighter's best attributes is his takedown defense, which is an impressive 87 percent through his first four UFC fights. This is a great aspect of Till's skillset, because his confidence in his takedowns allows him to be more fearless in committing to his Muay Thai and striking -- he simply does not have to be concerned with being taken down at will. He was able to commit to his Muay Thai against Velickovic, as he landed great standing elbows throughout the fight, which hurt his opponent and opened up a big cut. Till showed great standup in that fight, but with the announcement of his next fight on Thursday he will need to turn it up a notch in order to keep on the winning track.

Till's next fight is rumored to be in the main event of UFC Gdansk against the No. 6-ranked UFC welterweight Donald "Cowboy" Cerrone. "Cowboy" is one of the most game fighters in the sport and will always bring the fight to his opponent. Like Till, Cerrone has great Muay Thai skills and is known for preferring to strike. The undefeated Till will be making a huge step up in competition, as he has not fought an opponent ranked in the top 15. Cerrone will has a diverse skill set and will test all areas of the English welterweight's skills. Even though Cerrone prefers to strike, he has a great ground game and it would not be surprising to see him mix in some takedowns. Till will have to utilize his takedown defense and hope that his Muay Thai is superior to that of Cerrone. It will undoubtedly be an exciting fight, as most of Cerrone's fights are, and if Till is able to come out on top it will catapult him into stardom. With a victory, there is a good chance Till will be ranked in the top ten and on the fast track to a title shot.

Next Fight: Donald Cerrone, UFC Gdansk (October 21, 2017)

Tyson Pedro, UFC, Light Heavyweight

Pedro is undefeated as a professional mixed martial artist with six wins and no losses. Each of his six fights have ended in the first round. He has four wins via submission and two via KO/TKO. Pedro is a good boxer and also holds a black belt in Japanese Jiu Jitsu and a brown belt in Brazilian Jiu-Jitsu. The unknown of the Australian light heavyweight is his conditioning, because he has never fought past the first round in his professional career.

On Saturday, Pedro will be tested by veteran UFC light heavyweight Ilir Latifi. There is no guarantee Pedro's conditioning will be tested, as Latifi's fights have only gone past the first round in three of his eight Octagon appearances. This fight will likely be contested on the feet, as both fighters have 100 percent takedown defense through their careers. However, Pedro's takedown defense will be tested, as Latifi is a former member of the Swedish national wrestling team. Pedro will also be facing a veteran of the sport with Latifi having more than twice the amount of professional fights as the Australian. With a combination of Latifi's experience and wrestling, I expect him to try to grind on Pedro up against the fence to test his conditioning. This will be a big moment in Pedro's career, and if he can get past the veteran fighter it will vault him into the top 10 of the UFC light heavyweight division.

Next Fight: Ilir Latifi, UFC 215: Nunes vs. Shevchenko (September 9, 2017)

Check Status

Kudos to McGregor for a great showing in the boxing realm against the greatest boxer of all time, Floyd Mayweather. Conor surprised everybody by being very competitive through the opening rounds of a fight and even winning a few of those rounds. However, in the last three rounds Mayweather's conditioning took over and he stopped McGregor in the tenth round. With the boxing spectacle over, the debate is who McGregor will fight in his return to the Octagon. There is also uncertainty of how successful the Irishman will be in his return after taking the better part of nine months to train for a boxing match. After preparing for boxing, will his grappling and wrestling skills deteriorate? If his takedown defense suffers from the long layoff, it could be difficult for the UFC Lightweight Champion to step back into the cage.

There are three possibilities for "The Notorious" to face in his first defense of the UFC lightweight title. First is the rubber match with Nate Diaz. Diaz won the first fight when he submitted McGregor in the second round, and then McGregor won a decision in the rematch. Second, is a fight with Khabib Nurmagomedov in Russia. The third option is a fight against the winner of the interim UFC lightweight title fight between Kevin Lee and Tony Ferguson. Nurmagomedov makes the least sense for McGregor. He is arguably the most dangerous fight, and he missed weight in his last attempt to fight against Tony Ferguson. With well documented issues making weight, it is unlikely the UFC would risk spending the money on promoting a fight between Nurmagomedov and McGregor. The fight that makes the most sense is a matchup with the winner of the interim title fight. Kevin Lee seems to be a fast-rising star in the sport, and Tony Ferguson is the most deserving of the opportunity with an impressive nine-fight winning streak. It only makes sense for the champion to fight the interim champion to see who rules the division. However, the most likely challenger for McGregor upon his return to mixed martial arts is Nate Diaz. Their last fight was a war, Diaz is a fan favorite, and McGregor has voiced interest in a rubber match with the Stockton-based lightweight. This would be the most profitable fight for the UFC and is compelling due to the fighters splitting their first two meetings. It is almost the most favorable fight for "The Notorious," as Diaz likes to box, and the other opponents mentioned above have more grappling-based strategies. McGregors's coach, John Kavanaugh, said McGregor will make his return in 2018. It will be interesting to see who he chooses as an opponent as well as how polished his grappling skills are in his return to the Octagon.

Next Fight: TBA

Falling

After a disappointing outing against journeyman Sam Alvey, Rashad's career is in jeopardy. The loss marks his fourth loss in a row, and his second in a row to lesser-known fighters in Dan Kelly and Alvey. Evans, who made the jump to middleweight, has been underwhelming since changing weight classes. Even though he has been competitive in his two fights at 185 pounds, he still lost to two fighters who are nowhere near title contention. This is a stark contrast from the rest of "Suga's" career, as he has consistently fought fighters ranked near the top of the division for almost the last 10 years. The decline in competition shows that the aging fighter should consider calling it a career and stepping away from the sport. It is clear he cannot compete with top-ranked competition. Evans is also a very good analyst and could easily make the transition to that job in the realm of mixed martial arts. It is disheartening to see the former champion taking on middle-of-the-road competition and coming out on the losing end. Even his Division I wrestling credentials have not been helpful to him in the late stages of his career. With back-to-back losses to Dan Kelly and Sam Alvey, Evans needs to step back and evaluate where he stands in the sport, and ultimately make the decision to retire.

Next Fight: TBA

Jon Jones, UFC, Light Heavyweight

After a huge victory over Daniel Cormier via TKO at UFC 214, Jon Jones is once again in the news for all the wrong reasons. He reportedly failed a performance enhancing drug test prior to his fight with Cormier. The substance in question is reportedly Turinabol. Looking back at his track record since enhanced testing under USADA, it is difficult to know which Jones to expect when he comes back from the suspension he faces (rumored to be a minimum of two years and a maximum of four years). It is difficult to determine how Jones will be as a fighter because of how he looked in his most recent fight when he did not test positive for banned substances. Against Ovince St. Preux, Jones put forth his poorest performance in the Octagon. This admittedly could be due to being away from the sport for over a year, but it does not get around the fact that he could not finish St. Preux, who suffered a broken arm early in the fight. Then, in this fight with Cormier who is a far more skilled mixed martial artist, and after a layoff of over a year, Jones virtually destroyed Cormier, who had never been finished before UFC 214. When, and if, "Bones" does make a comeback, it will be very interesting to see if his performances are more like his fight with St. Preux or his UFC 214 contest with Cormier. Don't expect the saga of this investigation to end any time soon.

Next Fight: TBA