Here's a look at the transactions this week that had the most significant fantasy impact.
Erick Aybar, SS - activated from the 15-day DL
Andrew Romine, IF - optioned to Triple-A Salt Lake
Impact: Aybar missed a couple of weeks with a non-displaced fracture in his right big toe. The Angels' shortstop has put up some rather unremarkable numbers this year, as he returns to a .257 average, four home runs and 28 RBI in 91 games. While he's not likely to improve too much on those numbers, he could still be worth a look in deeper leagues. Maicer Izturis had been serving as the team's regular shortstop while Aybar was out, and will return to a backup role. Romine was 4-for-12 in seven games with the Angels.
Jordan Schafer, OF - placed on the 15-day DL (left shoulder)
Brandon Barnes, OF - contract purchased from Triple-A Oklahoma City
Impact: Schafer hasn't done much with the bat so far in his young career, as he holds a .612 OPS through 228 career games. However, he hasn't been completely devoid of fantasy value in some deeper leagues as he's stolen 26 bases in 96 games this season. He is now out indefinitely with a separated AC joint in his left shoulder. Barnes not only replaces Schafer on the active roster but should also receive the lion's share of playing time in center field. The 26-year-old batted .321 with 12 home runs, 81 runs scored, 69 RBI and 21 stolen bases in 106 games between Double-A and Triple-A this year. While he's too old to be considered a prospect, he could still have some value in NL-only leagues as long as he gets regular at-bats.
Josh Vitters, 3B - recalled from Triple-A Iowa
Brett Jackson, OF - contract purchased from Triple-A Iowa
Tony Campana, OF - optioned to Triple-A Iowa
Impact: The Cubs continued to shake things up this week, shipping utility man Jeff Baker to the Tigers and calling up a couple of highly-touted rookies. Vitters hit .304 with 17 home runs and 68 RBI in 110 games at Triple-A this season and will serve as the team's primary third baseman. Light-hitting Luis Valbuena will return to a backup role as a result. Jackson hit just .256 at Triple-A this year, but homered 15 times and stole 27 bases in 106 games. He should be a regular in the Cubs outfield, with Bryan LaHair and Joe Mather the most likely players to lose playing time as a result. Both Vitters and Jackson have the potential to help a fantasy team in most league formats. Campana hit .259 (41-for-158) with the Cubs, but failed to hit a home run in 70 games.
Matt Garza, RHP - placed on the 15-day DL (right elbow)
Brooks Raley, LHP - contract purchased from Triple-A Iowa
Impact: Garza hadn't pitched since he was pulled from a start July 21 after just three innings and was expected to start Tuesday. He has now been shut down for at least a few weeks due to a stress reaction in his right elbow and may not pitch again this season. Garza is just 5-7 with a 3.91 ERA and 96 strikeouts in 103.2 innings over 18 starts. He'll be replaced in the rotation by Raley, who is a combined 6-10 with a 3.58 ERA and 98 strikeouts over 130.2 innings between Double-A and Triple-A this season. He hasn't shown much of an ability to miss bats in the minors, so he would be a risky fantasy option at this point.
Travis Hafner, DH - placed on the 15-day DL (lower back)
Jason Donald, IF - recalled from Triple-A Columbus
Impact: Hafner's injury woes continue. The 35-year-old DH has failed to appear in more than 118 games in a season since 2007, and that trend will continue this year as he lands on the DL for the second time. "Pronk" was sidelined for about six weeks earlier in the year after undergoing surgery on his right knee, and he's now out indefinitely with stiffness in his lower back. While he's managed to club 11 homers in just 60 games, Hafner has struggled to a .239 average - the second lowest mark of his career. Cleveland will probably rotate several players in and out of the DH spot as it did during Hafner's first stint on the DL. Donald provides the Tribe with some infield depth and returns to a paltry .188 batting average, no home runs and four RBI in 19 games.
Giancarlo Stanton, OF - activated from the 15-day DL
Donnie Murphy, IF - placed on the 15-day DL (left hamstring)
Impact: Stanton missed a month due to surgery on his right knee, yet still managed to maintain his team lead in both home runs (19) and RBI (50). The 22-year-old outfielder appears to be well on his way to becoming one of baseball's most prolific home run hitters and is safe to activate in any league format. Austin Kearns and Scott Cousins shared right-field duties during Stanton's absence and could now see a reduction in playing time. Murphy batted just .194 (13-for-67) with three home runs and eight RBI in 33 games with the Fish.
Evan Longoria, 3B - activated from the 60-day DL
Will Rhymes, IF - optioned to Triple-A Durham
Impact: The long wait for Longoria's return to the lineup is finally over, as he returned to the field Tuesday. The 26-year-old third baseman missed more than three months with a partially torn left hamstring and returns to a .329 average, four home runs and 19 RBI over 23 games. He was 1-for-3 with an RBI in his first game back and is safe to activate in all fantasy formats. Recently acquired third baseman Ryan Roberts now gets bumped into a backup role due to Longoria's return. Rhymes hit just .228 (28-for-123) with one home run and eight RBI in 47 games with the Rays.
Todd Helton, 1B - placed on the 15-day DL (torn labrum)
Chris Nelson, 3B - activated from the 15-day DL
Impact: Todd Helton's season is over as he will undergo surgery on his right hip. The 38-year-old first baseman has struggled at the plate this year, posting a career-low .238 average while hitting just seven home runs and driving in 37 runs in 69 games. It appears unlikely at this point that he will earn a full-time role for the 2013 season as he is clearly on the decline. Matt McBride should serve as the Rockies' primary first baseman with Tyler Colvin backing him up. McBride hit .354 with 10 home runs and 77 RBI in 91 games at Triple-A this season before being added to the major league roster. He could have some mixed league value. Nelson will serve as Colorado's primary second baseman after missing a couple of weeks with an irregular heartbeat. He returns to a .256 average, five home runs and 23 RBI in 58 games.