PHOENIX -- Brian Giles doesn't know how much he's got left. So he checked into the Dodgers' Spring Training camp Thursday to find out.

"That's kind of why I came," said the 39-year-old two-time All-Star when asked if he wondered if it was time to retire.

"I almost said forget it before I signed. But if I didn't try, three or four years down the road I would look in the mirror and say, 'Why didn't I do this?' I should know after the first 10 days from how I feel the next morning."

Most players with Giles' accomplishments and injury history don't even attempt the one-last-shot thing. But if they do, the confidence that they can reclaim past glory oozes from them.

Giles, however, sounds uncertain, even though he doesn't need to look far for encouragement. His locker is right next to Eric Gagne's.

Giles is coming off a forgettable season with the Padres. In his glory days, he slugged at least 35 homers in four consecutive seasons, but in San Diego last year, he hit .191 with two homers in 61 games.

He went on the disabled list on June 19 and never came off, diagnosed with what was called a bone contusion, which can be a nice way of saying it's bone rubbing on bone. In that case, all the rehab in the world is meaningless, as the pain will return as soon as he starts running.

"I feel healthy, but you don't know until you start pounding on it," he said of his knee, which underwent micro-fracture surgery in 2007. "I've always said, if it's too hard or I can't play well, I'll walk away myself. I did regular offseason workouts and they went well."

The 2007 surgery was a temporary fix, as Giles rebounded in 2008 to hit .306 with a .456 on-base percentage. But last year, the knee flared up again.

"I re-injured the defect," he said. "From all of the MRIs, it is a significant injury, evidently. It's bone on bone, but I hope some of that scar tissue with the surgery didn't calcify. I'm curious to see how it feels when I get out there."

With Reed Johnson signed to replace Juan Pierre as the fourth outfielder, Giles is reduced to competing for the main lefty-pinch-hitter job. Giles has a .366 career average as a pinch-hitter and a 1.130 OPS.

Giles' most obvious rival for the bench role is Doug Mientkiewicz, who has physical problems of his own, with chronic pain in his throwing shoulder and, for the second year, must make the club on a Minor League contract.

"I think in Giles' case, he's curious, too, about his physical well-being," said manager Joe Torre. "He's in great shape, but he's had leg worries and he's here to see if this makes sense for him."

Giles said this will be his last shot, that there really weren't any other clubs interested and that the Dodgers made sense because of his home in the San Diego area. He's earned $81 million in his career, but signed earlier this month for $550,000 -- if he makes the Dodgers roster.

"The way last season ended, not playing the last 2 1/2 or three months and I'm not getting any younger, and the direction of a lot of organizations going to younger players, this opportunity came up," he said. "Like I said, if it's too hard on me physically, I'll know. It's been a pretty good career."