Houston Astros outfielder Lance Berkman had minor surgery Thursday to remove scar tissue from his right knee. Berkman, who hit .293 and hit 24 home runs in 2005, is expected to recover within 4-6 weeks, said Astros team doctor David Lintner. The Astros play their first spring training game March 2. The scar tissue developed as a result of surgery in November 2004 that repaired Berkman's torn anterior cruciate ligament.