PHOENIX — Manny Ramirez is sore and joking that he might be older than his 37-year-old birth certificate reveals.

"I'm like 40 years old. How much longer can I do this?" Ramirez said Tuesday, loudly enough for Dodgers teammate Andre Ethier to hear. "There he is, Andre, the superstar of the team. He's going to carry the load this year. I'm too old for that now."

Ramirez was set to join the Los Angeles spring training lineup for Thursday's exhibition against South Korea, eight days after agreeing to a $45 million, two-year contract that gives him the right to void the deal after one season.

After the Dodgers acquired him from Boston last July 31, Ramirez hit .396 with 17 homers and 53 RBIs in 53 games. Ramirez had been asking Dodgers manager Joe Torre to get into games and has been running the bases every day during workouts.

"If I'm going to steal bases and turn doubles into triples, I have to get on my horse," Ramirez said, smirking.

Still, there's a long time before the Dodgers' April 6 opener at San Diego.

"There is no need to prove anything, and plenty of time to get ready," Torre said. "But he's been all business and making up for lost time since he got here."

Ramirez is happy with the team and the addition of second baseman Orlando Hudson.

"I feel like I'm on vacation. How much longer can I play? I just want to enjoy it," he said. "I don't know what I'm going to do. It's another year. We'll all find out together."