PHILADELPHIA -- Pedro Martinez is in. Jamie Moyer is out.

The Phillies announced Monday afternoon that Martinez, who they signed to a prorated $2 million contract last month, will make his Phillies debut Wednesday night against the Cubs at Wrigley Field. Moyer, whose 40 wins since 2006 leads the Phillies, has been moved to the bullpen.

"We just felt that Pedro is pitching well enough that he deserves a chance to pitch in the rotation, and we hope it's an upgrade," Phillies general manager Ruben Amaro Jr. said.

"Based on our reports on how Pedro has pitched in his rehab starts, we felt it was time to move him into our rotation," manager Charlie Manuel said in a statement. "Jamie was a total professional and team player when we let him know of the decision to move him to the bullpen. He has been and will continue to be a very important part of this team."

The Martinez-for-Moyer switch is not a complete surprise.

It had been expected since Amaro said last week that left-hander J.A. Happ would remain in the rotation with Cliff Lee, Cole Hamels and Joe Blanton. The Phillies considered a six-man rotation, but they ultimately decided against that because it would take each starter off their normal routine.

But moving Moyer to the bullpen wasn't easy. He won a team-high 16 games last season, and had a team-high 10 wins this season. Despite the fact he has a 5.47 ERA, which is the highest in the National League and second-highest in baseball, the Phillies had to tread carefully.

"Clearly, he's got a lot more of a track record and he's done a lot more for us than your average pitcher," Amaro said. "Jamie has dedicated himself to his starts and to his performance and he will continue to do that, but we are trying to do what we can to win baseball games and win this division. And these are baseball decisions that are made collectively, and we feel it's for the betterment of our club."

Amaro also said Moyer took the news "extremely professionally. You'll have to talk to Jamie about it, but I'm sure he wasn't real happy about it. But at the same time, he understands that we're doing what we possibly can to have success. We just felt it was the right thing to do and he understands it."

It remains to be seen how effective Moyer, 46, will be in the bullpen. He has not pitched regularly as a reliever since 1996, when he made 13 relief appearances with the Red Sox.

Martinez, 37, has not pitched in the Majors since last season with the Mets. He went 1-1 with a 5.11 ERA (seven earned runs in 12 1/3 innings) and 16 strikeouts in three Minor League rehab appearances.

"We're going to watch him pitch and hopefully he's an effective starter for us," Amaro said. "I don't have expectations one way or another, other than we hope he is successful and he helps us win games."

Happ, who threw a shutout last week against the Rockies, will pitch Tuesday against the Cubs. Lee will pitch the series finale Thursday.

The Phillies also activated right-hander Chad Durbin from the 15-day disabled list. They have optioned right-hander Rodrigo Lopez to Triple-A Lehigh Valley to make room for Durbin.

In other news, the Phillies got results from J.C. Romero's MRI. Amaro said Romero has mid-grade tendinitis that is healing. Romero will not throw for another week or so, when he will return to Clearwater, Fla., to begin his rehab.