DALLAS, Texas (AFP) - Dallas Mavericks star Dirk Nowitzki will be sidelined indefinitely with a high left ankle sprain and sprained left knee, the National Basketball Association club announced Monday.

The 29-year-old German forward was injured in an 88-81 loss Sunday to the San Antonio Spurs, the Mavericks' third loss in a row, and his absence deals a major blow to Dallas hopes of qualifying for the NBA playoffs.

Nowitzki, last season's NBA Most Valuable Player, underwent an MRI exam Monday and is walking in a protective boot but without crutches. He was helped off the court after the injury and seen limping outside the locker room.

Nowitzki, a seven-time NBA All-Star who leads the Mavericks with 23.6 points and 8.8 rebounds a game, suffered the injuries when he fell awkwardly after blocking a shot by the Spurs' Ime Udoka with 3:18 to play in the third quarter.

After the fall, Nowitzki grabbed his left knee and grimaced in pain. Mavericks owner Mark Cuban indicated after the game he expected Nowitzki would miss two weeks, sidelining him for seven of Dallas' remaining 12 games.

At 44-26, the Mavericks are seventh in the Western Conference but only one-half game ahead of Golden State and two games ahead of Denver.

Should both clubs move past Dallas, the Mavericks - 2006 NBA runners-up - could miss the playoffs for the first time since 2000.

The Mavericks are only 9-8 since obtaining Jason Kidd from New Jersey, having yet to beat a club with a winning record since the deal.