ST. LOUIS (AP) _ St. Louis Blues defenseman Chris Pronger, the reigning NHL MVP, is scheduled to undergo knee surgery Tuesday and will be sidelined 4-to-6 weeks, the St. Louis Post-Dispatch reported.

Pronger, the Blues' captain who was slated to start in next month's All-Star game, played nine games after tearing cartilage in his left knee Jan. 4 against Nashville.

He had two goals and 15 points in that stretch, but decided on surgery after playing nearly 31 minutes Sunday in a 3-1 loss at Nashville.

``It's something we need to take care of now before it becomes a problem,'' Pronger said. ``You don't want it to become a problem in the playoffs when everything counts. Four weeks now could turn into two months.''

Pronger said he didn't believe the injury affected his play.

``You don't feel good, but you never feel good,'' he said. ``If I could play a game when I felt good, it'd be nice.''

Pronger leads Blues defensemen and ranks fourth among NHL defenders with 41 points, on six goals and 35 assists, and is plus-18. General manager Larry Pleau said the extent of the damage was revealed in an MRI exam Friday.

``He tried to play with it, but it kept bothering him,'' Pleau said. ``We thought about it for a couple of days here, and we felt the best thing to do is get it done now.

``He can play with it, but you never know what could happen. He could go down tomorrow, next week, the end of the year or not at all.''