Brandon Rush’s season is over after two games.

Memphis Grizzlies' Zach Randolph (50) makes contact with Golden State Warriors' Brandon Rush (4) during the first half of an NBA basketball game Friday, Nov. 2, 2012, in Oakland, Calif. Rush left the game with an injured knee after this play.

Rush’s agent, Mark Bartelstein, said Saturday that an MRI exam on the Golden State Warriors’ top reserve revealed a torn anterior cruciate ligament in his left knee. Rush, a former Kansas University standout, will have season-ending surgery in the coming days, and the typical rehabilitation time is at least nine months.

“He’s not doing great. He’s devastated as you can imagine,” Bartelstein said. “It’s a traumatic thing to go through for anybody. We’re going to figure it out and work with the Warriors and come up with a great plan to get him back. But for the moment, it’s devastating with surgery and rehab ahead of you.”

All the good vibes entering Golden State’s home opener fizzled in an instant.

Rush leaped in the air for a dunk when Zach Randolph fouled him from behind with 4:09 left in the first quarter of the Warriors’ 104-94 loss to Memphis on Friday night. Rush landed awkwardly, and his knee bent badly as he tumbled to the court.

The small forward got up on one leg, waved his arms in the air, and shook off teammates who tried to help. Rush covered his face in agony and eventually limped to the locker room with the support of teammate Jeremy Tyler and trainers.

Memphis selected third-string center Andris Biedrins to shoot the free throws. The home fans booed Biedrins — the former starter — before he missed both.

Richard Jefferson and second-round pick Draymond Green will be expected to fill the void in Rush’s absence. The Warriors could also use the disabled-player exception to sign a player who earns up to half of Rush’s annual salary.

Rush signed an $8 million, two-year deal in July — with a player option for the 2013-14 season — after coming over in a trade from Indiana for Lou Amundson last year. The 27-year-old Rush appeared in 65 of 66 games, posting career highs by shooting 50 percent from the field and 79 percent on free throws.

The forward fit seamlessly into coach Mark Jackson’s system and became one of the team’s best perimeter defenders, especially late in games.

Rush averaged 9.8 points and 3.9 rebounds in 26 minutes per game last season. He shot 45.2 percent from 3-point range — sixth-best in the NBA — and was Golden State’s best option off the bench.

Rush was drafted No. 13 by Portland in 2008 after leading Kansas to the national championship. He was then traded to Indiana along with Jarrett Jack and Josh McRoberts for Jerryd Bayless and Ike Diogu.

Rush tore the anterior cruciate ligament in his right knee in 2007 while at Kansas. And just as he did before, those around him believe he will make a full recovery.

“He’s strong minded,” Bartelstein said. “Right now it’s hard. I have no doubt he’ll do great.”