Roger Clemens made an unexpected appearance at the start of the Houston Astros' minicamp on Monday, pitching batting practice to prospects that included his oldest son, Koby. The 43-year-old right-hander hasn't decided whether he'll play a 23rd season. He led the major leagues with a 1.87 ERA last year but was plagued by back and hamstring problems late in the season. He limped off the field after just two innings in the World Series opener. Clemens said Monday his back and hamstring were healed, but he has doubts whether he could last another full season. "There will be a week I get up and I feel like I can do it again and then the next week, I don't want to get out in the outfield and start running those poles and doing those things," Clemens said. "If last year's World Series was it for me, I'm more than happy. I know we didn't reach our ultimate goal, but it was a lot of fun. I have a lot to think about."