OAKLAND -- David Ortiz, who on Monday suffered a recurrence of the irregular heartbeat that forced him to spend Aug. 19 at Massachusetts General Hospital, flew back to Boston yesterday for more tests.

He was admitted to the same hospital late last night.

The Red Sox' MVP candidate, who leads the American League in home runs and RBI, had plenty of company on the plane ride home.

Outfielders Manny Ramirez (patella tendinitis of the right knee) and Wily Mo Pena (sore left wrist) also were on the flight, so they, too, could be checked out by the organization's medical staff.

And there was a healthy Red Sox body accompanying them, as well. Left-hander David Wells, scheduled to start tomorrow night's game against Toronto at Fenway Park, was flown home early to rest up for the outing -- if he isn't traded first, but that's another story.

The story dominating the Red Sox surrounds all of the injuries that have plagued Boston since July 30. On that day, the Sox lost outfielder Trot Nixon (right biceps), and on Aug. 1 catcher and team captain Jason Varitek (left knee) went down.

Since then, Alex Gonzalez (oblique muscle) has been placed on the disabled list, and Ramirez and Pena also recently have been unavailable to manager Terry Francona, who entered last night's game against the Oakland Athletics at the Oakland Coliseum with only two healthy bench players -- outfielder Gabe Kapler and catcher Javy Lopez.

The major focus, though, is on Ortiz.

Ortiz spent the night of Aug. 19 in the hospital after having played in the third game of the five-game set with the New York Yankees at Fenway. After being checked out and given fluids, Ortiz left the hospital on Sunday, Aug. 20, and was in the lineup for that night's game against the Yanks. He even homered.

News of Ortiz's hospital stay surfaced early last week when the team was in Anaheim. He addressed that report and confirmed it Friday night in Seattle, saying that stress, fatigue and dehydration had caused his problem.

He remained in the lineup and hit three more homers, boosting his total to 47. But prior to Monday night's game, Ortiz experienced another episode of heart palpitations and was scratched from the lineup with what initially was called an "illness" by the Sox.

After the game, Francona told reporters what had happened to Ortiz, and that he was being sent home for further evaluation.

Yesterday, the organization released a statement from its medical director, Thomas Gill.

"David had experienced similar symptoms approximately 10 days ago. He was admitted to the hospital on Aug. 19, where he was fully examined by specialists and a series of tests were performed. Based on the results of those tests, and David's symptomatic improvement, he was cleared to play. David had not experienced any additional episodes of palpitations until Monday evening.

"With the recurrence of those symptoms, we would like David to be fully examined and tested before he is allowed to return to the field," said Gill.

There is no way of knowing when Ortiz will be back, able to add muscle to a Red Sox lineup that has had the look of a spring-training, split-squad group. The team, said Francona and general manager Theo Epstein yesterday, will not rush him back until he's ready.

"He has to know that he's fine," said Francona. "We'll get him in the lineup when we know it won't jeopardize his health. We don't feel like he's going to keel over. A lot of people have this, but we aren't going to take any chances."

That's the only way to approach the delicate situation, said teammate Mike Timlin.

"This game is nothing compared to a guy's health and his family," said the veteran reliever. "You don't play games with a person's health. I don't care what you do in life. He's someone we care about deeply. All I can do is pray for him right now."

While the injuries to Ramirez and Pena represent lesser health risks, they are nonethless real, said Francona and Epstein.

Pena, who had surgery to remove the hamate bone in his left hand in early June, has been experiencing pain in his left wrist that he says is unrelated to the surgery. He had to come out of Friday night's game in Seattle because of the pain.

Pena asked for a cortisone shot a few days ago, but the Sox decided to send him home for evaluation, thinking if a cortisone shot can help the problem, they can have him back in the lineup sooner rather than later, possibly by tomorrow or Friday.

The perception of the injury to Ramirez, meanwhile, is that it is just "Manny being Manny," one of those times when the Sox' cleanup hitter just decides he wants some time off, as has happened in the past. Ramirez had played in only one of the team's previous five games.

"This is a legitimate injury," said Epstein. "We've rested it and that hasn't worked. He wasn't going to be able to play here, so rather than have him looked at [tomorrow], he can be looked at sooner. The diagnosis [patella tendinitis] stands."

The Sox' lineup, though, hasn't been standing very strong in the face of all the injuries. But they won't give in to the "woe is us" attitude, they said in what amounted to a clubhouse chorus yesterday.

"We've lost our number-three [hitter in Ortiz], four [Ramirez], five [Nixon], seven [Varitek] and nine [Gonzalez] hitters," said third baseman Mike Lowell. "That's a lot. No offense to (the numbers three-four hitters the last two nights) -- Mark [Loretta] and Youk [Kevin Youkilis] -- but they aren't David or Manny. The teams pitch you differently when David and Manny are in there. But we have to go out and play hard."

Loretta agreed.

"In all my years, I've never seen such a situation with so many injuries to one team," said Loretta, an 11-year big-league veteran.

"But you have to control what you can control. The guys that go out there will play hard and try to win a game. We can't try to do too much. I can't be David. Youk can't be Manny. We have to play to our strengths. Put some guys on base, get the guy over and get him in. It's a different style, but that's what we're going to have to do."

It's a challenge, said Epstein.

"It's easy to be a leader and show character (when things are going well)," said Epstein. "Adversity represents a challenge for guys to show character and leadership to get through this."

skrasner@projo.com / (401) 277-7340