Caleb Williams says his hamstring injury was a "pretty serious" tear and he still doesn't know if he will play Sunday

Caleb Williams finally made it through a full practice. He still cannot tell anyone if he will play on Sunday.

The Bears quarterback completed his first full practice in almost four weeks on Thursday. Then he opened his news conference by getting ahead of the obvious question.

"Before you start asking, I do not know if I'm playing yet," Williams said.

He said there are still checkpoints to clear and a "stress test" to pass before the team decides if he is ready. Chicago holds its final practice of the week Friday at Halas Hall and flies to Atlanta on Saturday.

"I felt a pop"

Williams was hurt on a fourth-quarter scramble in a 9-3 home loss to the Vikings on Sept. 20. He described the moment for the first time.

"I felt a pop," Williams said. "That's why I looked back. I looked back just like everybody else does when you feel a pop. (You) think somebody grabbed you. And nobody grabbed me."

He left the field on a cart with tears in his eyes and a towel over his head. That image drew plenty of attention around the league. Williams said he will not apologize for caring. "I'm always going to show emotion," he said. "This is what I love to do. This puts a smile on my face. It's everything to me. So not being able to be out there was frustrating."

Not just a strain

For weeks the injury was described as a hamstring strain. Williams said that was wrong. He called it "a hamstring tear" and said it was "a pretty serious one."

When he was asked what grade of tear doctors gave him he would not say. "We got a grade, but I wouldn't say it's deserved to be put out there," he said. "After all the false ones. So next question." He also declined to explain why neither he nor the team corrected the earlier reports.

The Bears are taking it slow

Offensive coordinator Press Taylor said the staff wants to see how Williams feels the morning after a heavier workload. "We'll see how his body responds, how he feels the next day, how he feels in his typical movement patterns," Taylor said. He liked what he saw from a throwing session at Lambeau Field on Sunday morning.

Coach Ben Johnson has not named a starter. He said the short week ahead matters too because Chicago hosts the Patriots on Thursday night Oct. 22. "We want whoever is out there (at quarterback) to have a good rapport with the offensive line, with the operation, with our pass catchers," Johnson said.

The Bears are 3-2 after going 2-1 without Williams with Case Keenum and Tyson Bagent taking turns under center. Kickoff against the Falcons is noon Central on Sunday at Mercedes-Benz Stadium.