BOSTON -- The Yankees entered the season envisioning Damaso Marte as one of their primary eighth-inning setup men and a trusted arm to neutralize left-handed hitters late in games.

Thus far, neither of those plans have worked out, thanks to a lengthy battle with issues in his pitching shoulder. But Marte is hoping that it is not too late to make a contribution to the Yankees' playoff run.

The left-hander rejoined the Yankees on Friday as he was activated for the first game of a weekend series at Fenway Park. His next appearance will be his first in a Major League game since April 25, also in Boston.

"Too much time," Marte said. "I never felt like what I felt before in my shoulder. That was the first time. For seven years in a row, I've pitched, but this year my elbow didn't feel good. Now it feels normal."

In a corresponding roster move, the Yankees optioned utility infielder Ramiro Pena to Triple-A Scranton/Wilkes-Barre. In Marte's absence, the Yankees have pieced together a strong bullpen, thanks in large part to the emergence of Phil Hughes in a setup role and squeezing left-handed work out of Phil Coke.

Marte spent a good chunk of the summer throwing at the Yankees' training complex in Tampa, Fla., and sought the opinion of Dr. James Andrews to explain the tenderness in his pitching shoulder.

Andrews cleared Marte to resume pitching, and he made 12 appearances on rehab at Triple-A and in the Gulf Coast League, combining to go 0-1 with a 3.00 ERA, allowing 10 hits and four earned runs in 12 innings while walking four and striking out 10.

In seven games for the Yankees, Marte was 0-1 with a 15.19 ERA.

"It has been a long time," manager Joe Girardi said. "We expect him to help us out and get left-handed hitters out. He could be a situational lefty for us. We'll see how he does."

One issue during Marte's rehab was his velocity, which touched 93 mph but did not consistently sit there. He completed his assignment on Saturday but was excused for personal reasons, though he did throw bullpen sessions at Yankee Stadium while the team was on the road trip.

"I feel normal. My velocity right now is up and down, but we're working hard to get to the same level, 93 and 94," Marte said. "It's hard for anybody to [not] play baseball. We're working hard to keep going. We don't have to look back."

Girardi said that it was possible the Yankees could carry 13 pitchers until rosters expand to 40 players on Sept. 1. He said that Marte would likely be used to retire one left-handed batter and could pitch on back-to-back days, whereas Coke's role would not change.

"We've been careful with him, too," Girardi said. "We have not used Coke a lot lately. He's had a little break here. Coke is going to be asked to get important outs just like he was before."