Denver forward Kenyon Martin sat out the Nuggets' game against Minnesota on Sunday night because of a sore knee that still hasn't fully recovered from an offseason operation.

Martin has limped through the better part of Denver's first six games. He's averaged 14.2 points and 5.3 rebounds -- not far below his numbers from last season -- but his minutes have been down.

Coach George Karl didn't estimate how long Martin might miss.

"It's a sore knee," Karl said. "He is frustrated, we are frustrated. We're being conservative with what we do on it and how we manage it."