From Comcast SportsNetSAN DIEGO (AP) -- Lance Berkman is scheduled for season-ending surgery on his troublesome right knee Tuesday, leaving the St. Louis Cardinals without a dangerous bat as they try to secure a playoff spot.Cardinals manager Mike Matheny announced the news Monday before his team played the San Diego Padres. The defending World Series champions began the night with a 1-game lead over the Los Angeles Dodgers in the race for the second NL wild card.Berkman, who had surgery on the same knee in May, traveled to Houston on Monday to meet with the medical team that performed the first operation. The same group of doctors will perform the surgery Tuesday.Berkman's knee and other physical ailments have limited the switch-hitter to 80 at-bats this season. He was hitting .263 with two homers and seven RBIs.The surgery, which will remove meniscus from Berkman's knee, will be the sixth of his career. It will be the fourth operation on his right knee, which has caused problems all season.The 36-year-old Berkman is a .296 career hitter with 360 home runs and 1,200 RBIs. He batted .301 with 31 homers and 94 RBIs last year to help the Cardinals win their championship.