Red Sox sign OF Grady Sizemore

Grady Sizemore, a three-time All-Star whose career began to unravel in 2009 due to a seemingly endless string of injuries, has signed a one-year deal with the Boston Red Sox, the team announced Wednesday.

Sizemore will earn a base salary of $750,000, but has a chance to make a total of $6 million if he reaches specified performance bonuses.

Sizemore, 31, is a career .269 hitter with 139 home runs in parts of eight seasons with the Cleveland Indians. His best season came in 2008, when he hit 33 homers, stole 38 bases and finished 10th in American League MVP balloting.

But Sizemore has appeared in only 104 games since 2009 because of assorted injuries. He sat out the 2012 season with back and knee problems, and missed the entire 2013 season because of microfracture knee surgery.

"It's been frustrating. No one likes dealing with injuries, and I've had my fair share," Sizemore said Wednesday night on a conference call with reporters. "Hopefully that's behind me now and I'm just focused on moving on and starting the second half of my career."

Sizemore said he's had a "normal offseason" and that the Sox have a plan to try to get him on the field and keep him there.

"Obviously they're a great team and who wouldn't want to be a part of this group of guys and this organization?" he said. "Medically, they did a good job of laying out a game plan for me. There's a plan in place to keep me on the field and keep me healthy throughout the year."

The Cincinnati Reds were among several teams to express an interest in Sizemore, who has been working out this winter in Arizona with an eye on making a comeback.

Jackie Bradley Jr. still is the odds-on favorite to open the season in center field, but the Red Sox have brought in at least some semblance of competition with Sizemore.

Sizemore has close ties with Red Sox vice president Mike Hazen and manager John Farrell, both of whom were on the Indians' player development staff when Sizemore made his rise to stardom.

"We added Grady because, one, he's available and, two, it provides some competition," Farrell told reporters Wednesday at a town hall event in Boston. "We have to see, once we get to spring training, Grady's tolerance physically. We don't have a projected number of games that we look at that he might be available for. We have to gradually build that up, build his endurance up. That's how spring training will be spent with him."

Sizemore turns 32 in August and has had seven surgeries since September 2009: two for a sports hernia (2009 and 2011), one on his elbow (2009), one on his back (2012) and three on his knees (one on his left, two on his right). Signing Sizemore was just the type of low-risk, potentially high-return bargain Red Sox general manager Ben Cherington on Tuesday had said the club was looking for in advance of the opening of camp Feb. 15.

To make room on the 40-man roster, right-hander Brayan Villarreal was designated for assignment.

Information from ESPNBoston's Gordon Edes was used in this report.