Thunder's Kanter fractures forearm

Leading OKC Thunder reserve Enes Kanter has fractured his forearm while punching a chair.

Leading OKC Thunder reserve Enes Kanter has fractured his forearm while punching a chair. (AAP)

Oklahoma City forward Enes Kanter is out indefinitely after fracturing his right forearm punching a chair on Thursday night during the Thunder's NBA victory over the Dallas Mavericks.

Thunder coach Billy Donovan said X-rays showed the break. Kanter left the game for good with 7:34 left in the second quarter.

Kanter is one of the NBA's top reserves and is the Thunder's third-leading scorer at 14.4 points per game. He finished third in balloting for the league's top sixth man last season, and his scoring average is up this season.