Goran Reljic has withdrawn from UFC 90 due to a lower back injury, the fighter’s manager, Zoran Saric, confirmed Sunday with Sherdog.com.

“He really doesn’t know what happened,” Saric said. “He was training and went to bed. Next day he woke up and he couldn’t move.”

Reljic (8-0) was scheduled to fight Thales Leites in a middleweight bout Oct. 25 in Rosemont, Ill. Saric is waiting on a second opinion regarding his fighter’s injury, but after an MRI, he described it as “muscular.”

The manager expects Reljic to rest his back for four to six weeks and then reevaluate his status. Meanwhile, the UFC will have little time to find someone to fight Leites.

“They weren’t happy, especially because it’s short notice, but there’s not much we can do right now,” Saric said after notifying the UFC of Reljic’s withdrawal. “He’s in pretty bad shape. There’s no way he can accept the fight.”