NEW YORK, N.Y. - Brooklyn Nets guard Deron Williams will be sidelined indefinitely after new testing on his sore left side revealed a fracture of his rib.

The Nets said Thursday that an MRI revealed a fracture of the cartilage portion of the left 12th rib and that Williams will be evaluated in a week. There is no timetable for his return.

"Deron reported some soreness above this area over the weekend and as a result underwent imaging studies on Monday, which were negative. Yesterday during the game he reported a new onset of symptoms below the prior area of soreness. New imaging studies done today demonstrated the fracture," Nets medical director Dr. Riley Williams III said in a statement.

The announcement provides some clarity to what has been a confusing few days regarding the two-time Olympian's status since he was first injured Sunday in Miami.

The Nets then listed him as probable for their game Monday against Dallas, even though Williams appeared in obvious pain at the end of Sunday's game. He was later ruled out, but returned Wednesday against Boston after the Nets originally called him doubtful to play.

Williams came off the bench late in the first quarter but made it just 4 minutes before having to come back out of Brooklyn's 89-81 loss.

Williams has battled injuries since signing a $98.5 million contract in 2012 and has been coming off the bench since returning from a two-game absence following a strained right calf. He is averaging 13.9 points and 6.3 assists.

The Nets also announced they had recalled guard Markel Brown and forward Cory Jefferson from the Maine Red Claws of the NBA Development League.