ST. PETERSBURG -- Rocco Baldelli will begin a rehab assignment at Class A Vero Beach on Monday.

He will be in the designated hitter role on Monday, Wednesday and Friday of this coming week.

"Anything after that is going to be fluid, and we're going to work together and try to decide where we go from there," Baldelli said.

Baldelli currently is on the 60-day disabled list with a mitochondrial disorder, an abnormality that has kept him in a constant stage of fatigue.

Baldelli going to Vero Beach is "an ongoing part of the process," said Andrew Friedman, the Rays' executive vice president of baseball operations. "I wouldn't say at this point there have been any great revelations. But the important thing right now is that he feels good. So right now, we're going to be smart about this thing. And it's a cliche, but we're going to take it one day at a time, because as we've seen in the past things can change pretty quickly. It's hard to say with any great confidence about what's going to happen here in the next couple of weeks."

Friedman said how Baldelli's body feels after those initial three games and the manner in which he bounces back will dictate what the Rays will do going forward.

"But it's atypical for a rehab assignment," Friedman said. "Usually at the beginning, you can lay out the exact schedule of what someone is going to do, the expectations for getting them back to the Major League level. But this obviously is a different situation, and we're going to treat it as such and continue to monitor it very closely. It's certainly a positive development. That said, it's one step closer, but we still have a lot of work to do to get him back and helping the team win games."

According to the Collective Bargaining Agreement, the rehab assignment for position players is 20 days, but Friedman said he doesn't know if 20 days will be enough time -- which prompted a followup question regarding whether the Rays were hoping to find some flexibility in the rule.

"I don't know yet, because it's fairly unusual to have a guy go much longer than that," Friedman said. "... It's our sense that if we need more time, and at this point we have no idea of whether we will or won't, that there will be ways to figure it out within the rules."

Baldelli is optimistic about the prospect of being ready in the prescribed amount of time, but manager Joe Maddon cautioned that it's not just about Baldelli being ready to play.

"Part of it will be performance oriented," Maddon said. "That he's playing and he's playing well. We've got something good going on right now. When a guy like him is ready to come back, which we really want to happen, he has to be playing well, too."

Baldelli has not played since May 15, 2007. Under the terms of the long-term contract he signed after the 2005 season, the Rays had until April 1 to decide whether to pick up his $6 million option for the 2009 season, and they did not. By declining the option, Tampa Bay must pay him $4 million, and Baldelli will become a free agent at the end of the 2008 season. Had the Rays exercised the option, the team would have had to face the same question of whether to renew him for 2010 and 2011 at a cost of $17 million, or buy him out at $2 million.

Baldelli, 26, has a .282 career average in four Major League seasons with 48 home runs and 221 RBIs; he hit just .204 with five home runs and 12 RBIs in 35 games in 2007.