Updated

Lakers center Andrew Bynum hyperextended his right knee during the second quarter of Los Angeles' game against San Antonio on Tuesday night, a potentially serious blow to the Lakers' hopes for a third straight NBA title.

Bynum was hurt midway through the second quarter when he stepped on the foot of Spurs big man DeJuan Blair while getting back on defense. Bynum awkwardly tumbled to the court and briefly stayed down before walking under his own power to the locker room.

Bynum won't travel with the Lakers to Wednesday night's season finale at Sacramento, team spokesman John Black said. The center will have an MRI on Wednesday morning.

Any significant absence for Bynum could be a major problem for the two-time defending NBA champion Lakers, who had lost their last five games before taking on the Spurs.

Bynum is averaging 11.5 points, 9.5 rebounds and nearly 2 blocked shots in 54 games this season while patrolling the paint as the Lakers' most important defensive player. The 23-year-old's imposing size alongside fellow 7-footer Pau Gasol is the Lakers' biggest asset outside Kobe Bryant, and Bynum is in the midst of a remarkable defensive season.

But Bynum missed the first 24 games of the regular season following offseason surgery on his troublesome right knee, and he has a long history of problems with both knees. He took one game off in February to rest a bone bruise in his left knee.

He had surgery on his left knee in 2008 after dislocating his kneecap, keeping him out for 47 regular-season games and the first of Los Angeles' three straight runs to the NBA finals. The Lakers lost to Boston in the 2008 finals without Bynum, but they've won the last two championship series with Bynum in uniform.

Bynum also partially tore the meniscus in his right knee last season, but postponed surgery until summer to start all 23 playoff games in the Lakers' championship run — and to make a trip to the World Cup in South Africa.

The Lakers struggled in the first half against the Spurs, who rested Tim Duncan, Manu Ginobili and Tony Parker with the top seed in the Western Conference playoffs already wrapped up.