Mavs' Caron Butler has season-ending knee surgery

DALLAS (AP) -- Mavericks forward Caron Butler had surgery Tuesday to repair a torn tendon in his right knee, likely sidelining him for the rest of the season.

It's a big blow for Dallas and Butler, who is eligible for free agency this summer. The Mavericks were second in the Western Conference at 25-8 entering Tuesday night's game against Portland.

Butler is Dallas' third-leading scorer, averaging 14 points and 4.1 rebounds in almost 30 minutes per game. The Mavs have relied on him to draw defenses from leading scorer Dirk Nowitzki.

"We're a team of good individual players, but we're a team first," coach Rick Carlisle said. "We've got to pick up the slack as a group. The challenge for us is to get better defensively, that will trigger a lot of good things for us."

Carlisle said Butler's surgery "went extremely well, from what I heard." He said he's exchanged text messages with Butler.

"He's in unbelievably great, positive spirits," Carlisle said.

Carlisle said Nowitzki would miss his fifth straight game with a sprained right knee. Nowitzki is day to day.