CHICAGO -- Miami Heat power forward Chris Bosh left the United Center limping and upset Saturday night. Not so much at the pain in his left ankle as how it got there.

Bosh sprained the ankle in the Heat's 99-96 loss to the Bulls when Chicago rookie center Omer Asik fell on his leg chasing a loose ball at the end of the third quarter. Bosh was going after the rolling ball when Asik dove to the floor, collapsing Bosh's lower leg.

X-rays were negative but Bosh missed the fourth quarter and may have an MRI in the next few days in Miami to determine the extent of the injury. The initial prognosis is that it wasn't a severe sprain.

"C'mon, that is how guys get hurt, that is how serious injuries happen," Bosh said.

"You've got to watch people's legs. I know guys want to hustle and everything but we all want to play and provide for our families and have a job."

Bosh was immediately frustrated with Asik, who has worked his way into coach Tom Thibodeau's lineup mostly through hustle and fighting for loose balls. Before he left the floor, Bosh shook hands with Asik but still was salty about the play after the game.

"We all want to be healthy and that is very important," said Bosh, who had 11 of his 17 points in the third quarter before the injury. "If it is by somebody's leg, don't dive for the ball, it's too close."

The Heat ended the game without two of their three stars as LeBron James missed his second consecutive game with his own sprained left ankle. James tested out the injury before the game on the court but had trouble cutting and was held out.