There were 140 qualified batters last year that had at least 502 plate appearances on the season. Duffy ranked 140th in ISO in that group with a .072 mark. There were four pitchers (minimum 50 PA) that had higher ISO scores than Duffy last year. Yes, Duffy hit for a high average and reached base at a career-best .361 clip, and tied a career-high with 12 steals, but these numbers are near impossible to roster in standard mixed leagues since he only qualifies at third base. He has the OBP skills to hit high in the order, and even lead off, but putting him in the middle of the order would be troublesome because he simply lacks consistent extra-base power. His best swing is one where he filets the ball to the opposite field, which helps push his average up as opposing defenses cannot shift him in the traditional sense. In two-strike counts, teams would be wise to reverse shift him and force him to roll over on something to the shortstop.

Duffy injured his heel prior to the 2017 season, and various setbacks prevented him from making a single appearance during the campaign. Prior to missing the 2017 season, he'd played in just 91 games in 2016 due to an Achilles injury. At this point in time, Duffy is in line to be healthy for spring training. The Rays retained the arb-eligible Adeiny Hechavarria, maintaining an insurance policy in case Duffy's injury issues rear their ugly head once again. With a career line of .281/.324/.395 and a modest 15.4 percent strikeout rate, Duffy has built a respectable resume at the big-league level, but his power is modest and that limits his appeal at a suddenly talent-rich shortstop position. Considering his history of injuries, it wouldn't be a surprise if Tampa Bay limited Duffy's usage during the early stages of the upcoming season.

Duffy's star-crossed 2016 included a slow start in San Francisco, a trade deadline move to the Rays, and season-ending Achilles surgery in early September. Despite the hiccup, he's on track to be fully ready for spring training. Duffy is expected to take the reins as the starting shortstop in the coming season and will look to produce numbers much closer to his solid 2015 rookie season with the Giants, when he slashed .295/.334/.428 with 12 homers and 77 RBI. The 25-year-old saw a regression in all of those categories last season over 246 fewer plate appearances than the prior year. With a clean start and full health, however, Duffy could prove to be a valuable source of fantasy production in multiple categories, particularly extra-base hits, RBI, stolen bases, batting average and OBP.

Other than teammate Brandon Crawford, Duffy has to be considered one of the more pleasant fantasy surprises of 2015. Never a highly-regarded prospect, Duffy had to hit his way onto the 25-man roster in spring training. He did just that, and never stopped hitting, forcing the Giants' hand to make him their everyday third baseman following the release of Casey McGehee. Despite never hitting more than five home runs in the minors, Duffy finished the 2015 season with 12 to go along with 77 RBI and 12 stolen bases. While those numbers aren't astronomical, they definitely were useful to fantasy owners who likely picked him up for nothing. Unlike fellow Rookie of the Year finalist, Kris Bryant, Duffy doesn't have a very high ceiling. What we saw from him in 2015 is probably what we are going to see going forward, but there is definitely value in that.

Duffy was an 18th-round pick out of Long Beach State in 2012 and he has ascended the minor leagues with little fanfare. Since being drafted by the Giants, he's shown major strides in his ability at the plate, hitting .332/.398/.444 with a 10.1% walk rate and stealing 20 bases at Double-A Richmond in 2014 to earn a big-league callup as part of the revolving door at second base. Duffy was overmatched during his taste of San Francisco, but he's hitting enough in the minors to be considered a potential utility option in the not-so-distant future. With a 6-foot-2 frame, he may eventually develop more power, but it hasn't surfaced in the form of home runs yet. Duffy has been used primarily as a shortstop in the minors, and he may become a coveted trade target by teams looking for a utilityman capable of exceeding expectations. Look for Duffy to advance to Triple-A in 2015, where he'll likely spend most of the season unless injuries ravage the team's infield depth.