BOSTON – The Boston Red Sox put center fielder Mike Cameron back on the 15-day disabled list Monday and recalled outfielder Daniel Nava from Triple-A Pawtucket.

Cameron has been playing through an abdominal injury for most of the year. He missed 34 games when he went on the DL early this season.

“I’ve had to make some adjustments that I haven’t had to make in my life,” he said of the recurring pain. “It’s uncharted. That’s why I’ve told you guys I’m day-to-day. I’ve tried to do my best to explain some of the things I’ve gone through and some of the limitations I’ve had.”

Boston Manager Terry Francona has seen Cameron fight to stay on the field, but knew it was time for him to rest.

“It was being apparent it was a struggle. He has been battling it unbelievably. I don’t know how he was,” Francona said before the game against Cleveland. “We’re going to put him on the disabled list, get him some rest and see how he does. If that doesn’t do it certainly surgery’s the next option.”

If Cameron does need surgery, it would end his season.

“I think there were times he was willing himself to try and go out there to help us win,” Francona said. “I don’t think people realize what he was going through.”

Limited to just 48 games this season, Cameron has a .259 average with four homers 15 RBI.

Nava batted .286 with one homer and 16 RBI in 29 games before being demoted on July 22.

Second baseman Dustin Pedroia, sidelined with a broken left foot since June 26, has been running, but the club would like to keep him from doing too much. Pedroia has already been hitting and taking grounders.

Outfielder Jacoby Ellsbury, on the DL since May 28 with fractured ribs, will play his second game for Triple-A Pawtucket on a rehab assignment tonight.