Watson, who was in a sling in the locker room after the game, will undergo an MRI on Monday.
"We took an X-ray and it did not show anything," Bulls coach Tom Thibodeau said. "We'll know more (Monday). We'll check how the swelling is, check what the doctors say."
Watson was escorted off the floor by team trainer Fred Tedeschi and appeared to be in serious pain before being walked directly to the locker room. He was replaced by John Lucas III.
Meanwhile, guard Rip Hamilton was a late scratch before Sunday night's game because of a sore groin. He is day to day.
"He had a tweak, so it was a game-time decision," Thibodeau said. "We wanted to play it safe. We wanted to make sure it was good. We decided at the last moment to sit him out. He tweaked it during the Clippers game. We did a walk through this morning and Rip participated in it."
Ronnie Brewer started in Hamilton's place.
"Earlier today Rip sat out of shootaround because he was a little banged up, but we thought he was going to give it a go tonight," Brewer said. "Everybody assumed that he was going to dress out. When everybody came in from shooting and their uniforms on, he didn't put his on. So we assumed he wasn't going to go."
Signed to a three-year contract by the Bulls after being bought out by Detroit, Hamilton is averaging 12 points this season. He was brought in to add height to the backcourt and help take some of the load off reigning MVP Derrick Rose.
Nick Friedell covers the Bulls for ESPNChicago.com. Information from The Associated Press was used in this reported.