The NL East leaders are hoping it will be a vintage performance.
Martinez finalized a $1 million, one-year contract with the Phillies on Wednesday and can earn up to $1.5 million in incentives. The three-time Cy Young Award winner hasn't pitched since last season and won only eight games in 25 starts over his final two seasons with the New York Mets.
"I might surprise you, I might not," Martinez said. "It's going to be really fun to go find out."
The Phillies are hoping Martinez has enough left to help them repeat as World Series champions. His dominating 20-win, 200-strikeout seasons are well behind him, but a healthy Martinez could provide a boost to a starting rotation that has been hit hard by injuries.
"I don't expect to be the same Pedro that I was when I was 26," the 37-year-old right-hander said. "There's a lot of innings I've pitched since then. It's not the same, but I still feel like I can still bring something to the table."
Martinez will need at least a few starts in the minors before he's ready to join Philadelphia's depleted rotation. The eight-time All-Star was placed on the 15-day disabled list with a shoulder strain but will be with the Phillies for their four-game series in Florida beginning Thursday.
General manager Ruben Amaro Jr. said he could pitch for the major league team in two to three weeks.
"Of course there's some risk here," Amaro said. "But we'd rather risk it on someone of his caliber and who knows how to win."
The risk stems from Martinez's age, his 2,700-plus career innings and the three consecutive injury-riddled seasons that derailed his career in New York. He made frequent trips home to the Dominican Republic last year to visit his dying father, an emotional burden he couldn't shed once he got the ballpark.
"The last few years have been horrible," Martinez said. "I'm not saying horrible because of the results. I haven't felt the way I wanted to feel. I wasn't the same Pedro you were accustomed to seeing."
The free agent pitched in the World Baseball Classic before this season. He went 5-6 with a 5.61 ERA for the Mets last year and won only 32 games for them over the life of a $53 million, four-year contract.
"I think I was too brave sometimes, or stupid sometimes, for pitching not in the regular health that you should have been in," Martinez said. "Being a veteran, you should know that. Sometimes your desire, your inner thoughts about competing and the way you feel about competing, drags you to do sometimes things that you shouldn't do."
Martinez was upbeat, cracked jokes and told amusing stories in a wildly entertaining 45-minute press conference that ended with him holding his No. 45 jersey.
He said he was picky about what team he wanted to pitch for and spurned other organizations to pitch for the Phillies. Martinez hoped the Mets would show interest but understood why they passed.
"I didn't do as well as I wanted to," Martinez said. "I'm pretty sure they know it."
The defending World Series champion Phillies lead the division by four games over the Marlins despite dealing with injuries in their rotation. Brett Myers had hip surgery in June. Antonio Bastardo, who replaced Myers, landed on the disabled list after making five starts. They have used nine starters through 86 games. They used only seven starters last season.
Martinez said if his health fails, he'll walk away.
"I'll be the first one convinced, really convinced, if I can do it or not," Martinez said. "If I don't do it, I'm going to go on and take myself out of baseball."
He won the Cy Young Award in 1997, 1999 and 2000 and has led the AL in ERA, wins and strikeouts.
"I bring with me a legacy, I bring with me my last name," Martinez said.
Adding Martinez isn't expected to prevent the Phillies from pursuing All-Star Roy Halladay. The Toronto Blue Jays are listening to offers for the 2003 AL Cy Young Award winner, and Philadelphia has already expressed strong interest.
"This doesn't preclude us from doing other things with the club," Amaro said.
The Phillies came away impressed after watching Martinez pitch in the Dominican Republic. Amaro said Martinez threw mostly in the high 80s but topped 91 mph in workouts.
"We felt like he threw well enough that it was the right time to make a move on him," Amaro said.