Here's a look at the transactions this week that had the most significant fantasy impact.
Ben Sheets, RHP - activated from the 15-day DL
Impact: The 34-year-old Sheets missed the entire 2011 season as he underwent surgery on his ailing right elbow, and there had been doubts about whether he'd ever pitch again. He put those doubts to rest this year as he started eight games for Atlanta, going 4-4 with a 3.54 ERA before landing on the DL with right shoulder inflammation. That latest injury kept him out of action for almost a month, but he is once again available to pitch. Although he is not yet penciled in for any starts, it would not be surprising to see him get a spot start or two over the final weeks of the season.
Travis Hafner, DH - activated from the 15-day DL
Impact: Hafner will be used sparingly over the remainder of the season after he missed six weeks with a herniated disc in his lower back. Manager Manny Acta said the oft-injured designated hitter should play about three times a week, which obviously hinders his fantasy value. The 35-year-old Hafner returns to a .239 average, 11 home runs and 32 RBI over 60 games and is probably only worth activating in the deepest of fantasy leagues.
Mike Napoli, C - activated from the 15-day DL
Impact: The Rangers' All-Star catcher returned to the lineup last Saturday after missing more than a month with a strained left quad. Napoli had a good day at the plate, as he went 2-for-3 with a homer and three RBI against the Mariners. While he will likely split time behind the dish with Geovany Soto, the Rangers will still probably try to get Napoli into the lineup on a regular basis. He returns to a .223 average, 17 home runs and 40 RBI through 92 games and is still one of the more productive offensive catchers in baseball.
Sean Rodriguez, IF - activated from the 15-day DL
Impact: Rodriguez has received a fair amount of playing time in Tampa Bay this season, seeing significant time at second, third and shortstop. Unfortunately, he hasn't capitalized on the opportunity as he returns to a woeful .215 average, six home runs and 32 RBI in almost 300 at-bats. He missed almost a month with a hand injury and will now probably be used on a limited basis as infield depth. He isn't likely to carry much, if any, fantasy value over the remainder of the season.
Jorge De La Rosa, LHP - activated from the 60-day DL
Impact: De La Rosa hadn't started a game since May last year as he underwent Tommy John surgery on his left elbow. While he comes into the 2012 season with a lackluster 4.90 career ERA, his numbers have been significantly better than that the last three years. From 2009 to 2011, De La Rosa was 29-18 with a 4.18 ERA and 358 strikeouts in 365.2 innings. It remains to be seen whether De La Rosa can return to his pre-surgery form, so fantasy teams may want to steer clear. Alex White has been bumped to the bullpen to make room in the rotation for De La Rosa.
Andy Pettitte, LHP - activated from the 60-day DL
Impact: Pettitte ended up missing about 12 weeks due to a broken ankle suffered during a June 27 start. The now 40-year-old left-hander came out of retirement earlier this season and went on to start nine games for the Bombers before the injury. The results were impressive: a 3.22 ERA, 1.09 WHIP and a strikeout rate of just over one per inning. He pitched five shutout innings against Toronto on Wednesday and figures to be a key part of the Yankees' playoff run. Activate him immediately.