After missing 28 games, Williams was expected to play for the Kings at Dallas on Friday night.
Williams broke his leg in Phoenix on Dec. 26. He had 24 points in 33 games before his injury.
"I'm thrilled I'm back," he said earlier this week. "I want to be a part of [the playoff push]. That was also a driving force on me working hard and getting back in the lineup real soon."
The Kings are firmly in the Western Conference playoff picture even though their projected top line of Williams, center Ryan Smyth and high-scoring left wing Anze Kopitar has barely played together this season. Smyth returned from a six-week absence with an upper-body injury for the same game in which Williams was injured.
"My philosophy on injured players is that they don't lose their position because of an injury," Kings coach Terry Murray said. "I'll be careful about putting him back into a high-end situation too because I don't want him to take a step backwards and lose some confidence.
"But I have a feeling: Willie's outlook on this whole thing through the injury, how positive he's been and how hard he's worked, being ahead of schedule, he's going to be able to get in there and do the job and not step away from where he was."
Los Angeles acquired Williams in a trade with Carolina last March.
ESPNLosAngeles.com and The Associated Press contributed to this story.