CHICAGO -- Bulls center Joakim Noah injured his left shoulder again during the second quarter Friday night against the Dallas Mavericks and did not return in Chicago's 83-77 loss.

He will have an MRI on the shoulder Saturday, according to Bulls coach Fred Hoiberg.

The Bulls, after initially saying the injury was a separated shoulder, clarified later Friday that Noah had suffered a dislocation.

A shoulder dislocation occurs when the top of the arm bone pops out of the shoulder socket, putting the connective tissue and nerves in the joint at risk of being damaged. A shoulder separation happens when a ligament that connects the collarbone to the shoulder blade is torn.

Noah was injured with 9:41 left in the second quarter after he got tangled up with Mavericks center JaVale McGee.

Noah immediately grabbed his shoulder and screamed as it appeared to pop out of place. He went straight to the locker room to be evaluated by the Bulls' medical staff.

The injury had a noticeable impact on his teammates during and after the game.

"Without a question," Bulls forward Taj Gibson said. "You've been going to war with this guy, all kind of different circumstances over eight years, a guy that you pride yourself with especially in practice on a daily basis, and he's one of the emotional leaders on this team.

"It kind of hits you in the heart seeing him on the bench, seeing him on that table like that. I kind of got flashbacks to how when Derrick [Rose] got hurt. You don't want to see your man go down like that. It was frustrating."

Noah initially injured the shoulder during a Dec. 21 loss to the Brooklyn Nets and missed almost a month of action. An MRI showed a small tear in the shoulder, but Bulls Hoiberg said several weeks later that he was confident that surgery would not be needed.

After Friday's game, Bulls swingman Jimmy Butler said he spoke to Noah in the locker room before he left the United Center and said Noah was understandably upset.

"He's down as he should be," Butler said. "This is the game he loves. He wants to play for this team. Just being out with the same injury, something like that, I don't know what it is, but I know that he wants to be out there with us."

While the Bulls aren't sure what Saturday's MRI will show, Bulls players seemed to fear the worst.

"Anything can happen up here, man," Rose said. "We're saying that now this year. That's something that we never would have thought would have happened. But he's a big piece to our team. He is going to miss a little while now if it is dislocated. We just got to find a way to just grind games out. If we're up throughout the game we got to find ways to maintain the lead and play that way."