MIAMI -- It has now been more than eight months and counting since Jason Bay last appeared in a regular-season game, and the clock is still running. The intercostal strain in Bay's left rib cage, which officially landed him on the disabled list Thursday, will force him to miss at least the first seven games of the regular season.

"It was devastating at first," Bay said Thursday at the team's Spring Training complex in Port St. Lucie, Fla. "You put in all that time in the offseason, you come off a concussion, and then all of the sudden you come into spring and the last week or so of spring, it kind of felt like I was starting to catch a stride.

"Things were getting exciting. And then all of the sudden to just have a derailment -- it was a tough day yesterday, but what's done is done. You just move on and the silver lining is that, knock on wood, it's not that bad. There will still be a full season ahead of me."

The Mets on Thursday officially placed Bay on the 15-day disabled list retroactive to March 25, making him eligible to return as soon as April 9.

After visiting with doctors on Wednesday in New York and receiving a cortisone injection in the affected area of his rib cage, Bay has reason to believe that's a realistic goal.

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"It's not like I cough and I wince over in pain," Bay said. "I can feel something there, which is a good thing. They told me that it's not a biting pain, just enough to let me know there's something going on.

"Things change. But in talking to the doctors, they think it's very reasonable to think I could be out there for [April 9], which would be nice."

Originally feeling "a little sting or stab" in his left side prior to Tuesday's game, Bay took one additional round of batting-practice swings before shutting himself down. From there, he met with doctors in Port St. Lucie, before flying Wednesday to meet with the team's medical staff in New York. The prescription, quite simply, is rest.

Though Bay's injury may not be significant, it was hardly his desire after missing the final two months of last season with a concussion. Now more than a year removed from signing a four-year, $66 million contract, Bay has been anxious all spring to prove that his .259 average and six home runs in 95 games last season were flukes.

"There's not really a good time to get injured -- especially a few days before the season starts, especially for me really wanting to get back out there," Bay said. "There's a little bit of a hit, but at the same time, we're trying to do the thing where we take an extra day now rather than sit for a month."

"Sure, it's going to put a damper on it, but you have to address it," manager Terry Collins said. "I'd rather get it out of the way. If the only thing we're going to face is losing Jason Bay for nine days, we're going to have a pretty good season. We'll deal with it, we'll find the guys to pick up some slack and everybody's got to perform, everybody's got to play a part here, everybody's got to contribute."

In Bay's absence, rookie Lucas Duda has made the team and will start regularly in left field -- though a Mets official said on Wednesday that Willie Harris will start Opening Day against hard-throwing Marlins right-hander Josh Johnson.

After a tremendous regular season at Triple-A Buffalo last year, Duda stumbled out to a 1-for-34 start following a callup last September. But he rebounded to hit 16-for-50 with four home runs the rest of the way, earning him an invitation to big league camp and a chance to make the team.

Though he has spent much of the past month learning the nuances of right field, Duda said he still feels more comfortable in left. Quiet and reserved by nature, he is beginning to feel comfortable in the Majors, as well.

"I know what to expect now," Duda said. "But I don't know if you can ever be ready for the big leagues."