OAKLAND -- The massive slump the Red Sox are in seemed far less relevant by the end of Monday night, when the club revealed that David Ortiz, the team's star designated hitter, suffered a recurrence of the rapid heartbeat he was experiencing 10 days ago. Ortiz will fly back to Boston on Tuesday morning to undergo further medical exams.

"He's going to go back to Boston and he's going to get a clean bill of health before we let him play again," said Red Sox manager Terry Francona after Monday's 9-0 loss to the A's. "He wanted to play; we just can't do that. We can't play him like that. We just can't do it. I know [general manager Theo Epstein] is in agreement with me. We sat in here with [Ortiz] and, as much as we want to win, we can't do it. We're just going to make sure he's OK."

It was recently revealed that Ortiz was hospitalized the night of Aug. 19 after experiencing dehydration and stress. He checked out the next morning, given a clean bill of health by physicians at Massachusetts General Hospital, and played on Aug. 20 against the Yankees, hitting a home run.

Ortiz played the first six games of this West Coast trip, belting three homers to give him a Major League-leading 47 this season. But it was announced shortly before Monday's game at Oakland that Ortiz was scratched from the lineup because, according to team spokesman Peter Chase, "he wasn't feeling well."

After the game, Francona told reporters that Ortiz had a recurrence of what went on during the five-game series against the Yankees at Fenway.

Wily Mo Pena, one of Ortiz's closest friends on the Red Sox, was aware that Ortiz was again feeling the irregular heartbeat on Monday.

"He told me it was still bothering him a little bit," Pena said. "That's why they took him out of the lineup. He doesn't know where that's coming from. He feels all that stuff just going boom boom boom, but nobody knows where that is coming from."

Francona emphasized multiple times to reporters that the Red Sox were sending Ortiz home as a precaution, and were optimistic that the slugger would be OK.

"We honestly think he's OK," Francona said. "He's not light-headed. Again, I just have a responsibility to do what's right. It's precautionary; I don't know, [if there's] a one in a million [chance of risk], whatever, it's just not going to happen. If there's any risk at all, we're not taking it."

Is an irregular heartbeat a fair enough synopsis of what Ortiz is feeling?

"Yeah, I think that's correct," Francona said. "And, again, I can't get too specific because I just don't know. I don't pretend to know. We just can't let him ... again, to reiterate, the games are important, but we have a responsibility to do what's right."

That was a sentiment echoed throughout the Boston clubhouse.

"This game is nothing compared to somebody's health and somebody's family," said Red Sox reliever Mike Timlin. "You don't play games with people's lives. I don't care what you do. All I can do right now is pray for him."

Ortiz had an in-depth discussion with reporters last Friday about his scare in Boston, and seemed confident that the issue was behind him.

"I'm a healthy son of a [gun]," Ortiz proclaimed to reporters on Aug. 25. "Yeah, everything was fine. It's just stress. When you stress out, your whole body can change in a minute. That's what was happening."

The Red Sox hope to get more answers when Ortiz returns to Boston.

"He was in a good mood today," Pena said of Ortiz. "I think after he went and talked to the trainers, after they took him out of the lineup, he told me it started bothering him again. So I don't know yet what is going to happen."