Roman Modrowski of the Chicago Sun-Times reports that  patience is wearing thin at the Bulls camp. After a 26-point loss to the Timberwolves on Tuesday and a bad practice by temperamental point guard Jamal Crawford, Bulls coach Bill Cartwright got serious.

Crawford, 22, refused to follow Cartwright's instructions on how to run the triangle offense. The third-year point guard hasn't been thrilled with having to battle rookie Jay Williams for the starting spot. And that frustration boiled over when he refused to pass the ball into the post and instead took the shot himself.

Cartwright halted practice to reprimand Crawford, who angrily took himself out of the scrimmage and told a teammate to sub in for him. A furious Cartwright ordered Crawford to leave practice.

"We're going to test these guys, as far as them being able to do what we need them to do on the floor,'' Cartwright said. "I didn't feel like Jamal was prepared to practice, so we just asked him to step off and go home.

"He'll be back tomorrow, and tomorrow's another day.''

According to one player, Crawford has displayed this kind of frustration throughout camp as he has split time and starts with Williams. But Cartwright disagreed. "Jamal's been fine,'' Cartwright said. "He's been working hard and playing hard, as far as I'm concerned.''

To add injury to insult, Bulls forward Tyson Chandler left practice after suffering a concussion.

Chandler suffered his damage while chasing a loose ball headed out of bounds and colliding with teammate Lonny Baxter. Chandler's head hit the court face first, chipping a tooth and giving him a concussion. Chandler was taken to the hospital for precautionary tests.

"I went over to the hospital, and he looks to be fine,'' Cartwright said. "He has a bump on his forehead and a chipped tooth.'' Chandler was released from the hospital and is expected to miss two games this weekend.