However, that doesn't mean Timmons is a certainty for Sunday's game in Chicago.
"He's probably not game ready yet," LeBeau said. "He's getting a lot closer than he was the first part of the week."
"I'm not 100 percent at all," said Timmons. "But I'm trying to get there."
If Timmons can't play, Fox will make his second start for the Steelers at Larry Foote's old mack inside linebacker position. Fox led the Steelers with nine tackles last week and he recovered a fumble.
"All you're seeing is him getting an opportunity to do what he's been doing on special teams ever since he's been here," LeBeau said Fox, who signed with the Steelers after four seasons in Kansas City. "We've always liked him. He has good speed, he's an aggressive player, he's got real good playing strength, he's a smart guy, and he competes. In games, he goes out there and gives you his best performance when the chips are on the table, and that's what you're looking for."
Timmons also played a position on the dime defense that calls for safety-like coverage skills. In fact, it's a position that had been manned by Troy Polamalu prior to last season. Polamalu, of course, is out with a sprained knee.
"We played that position in the second half last week with Keyaron and Ryan Mundy and those two players did an excellent job there," LeBeau said. "We're fortunate we have good depth there. We'll be very pleased if Lawrence is back and ready to go, but those other players will definitely get some snaps there whether he's up or not. I don't think he'll be ready to go a full 60 minutes taking every snap on defense."
The only other player to miss Thursday's practice was wide receiver Limas Sweed, who's doubtful for the game with a mid-foot sprain.
SWEET HOME CHICAGO
Last year's No. 1 pick Rashard Mendenhall missed most of last season with a broken scapula, and on the first play of his much-anticipated return the running back slammed into quarterback Ben Roethlisberger while taking the ball and was tackled after a 1-yard gain.
Mendenhall went on to finish the game with 6 yards on 4 carries after averaging only 3.1 yards per carry in the preseason. Mendenhall would like nothing better than to show Steelers fans why he was a first-round pick this Sunday when he goes back to his hometown to play the Bears.
"It'll be good to go home," he said. "I grew up around Soldier Field and it'll be special to play there."
His take on a running game that averaged only 1.6 yards per carry in the opener?
"It's only been the first game and we played against a big-time defense," he said. "People can only see what's on TV. We watch film and we do this for a living, and I feel we'll get everything straightened out that we need to." Mendenhall said he's "confident in what I'm doing. I feel good mentally and physically and am just moving forward."
As for the collision with Roethlisberger: "Just a miscue," he said. "Stuff like that happens, particularly early in the season. It was unfortunate that it happened at that time, particularly when all eyes are on you. But it is what it is. It was a mistake and you learn from it."
Because of a slight hamstring injury to Keenan Lewis, fellow cornerbacks Joe Burnett and Keiwan Ratliff will be active this Sunday and will step into the role of punt gunners against the Bears' dangerous return man Devin Hester.
Neither of the two ever played the position before this preseason, not even in high school, but Ratliff doesn't see it as gamble by the Steelers.
"I wouldn't look at it as a risk, because I feel Joey and I are top-notch athletes," Ratliff said. "Being a gunner is just about being an athlete – getting down the field and making some type of tackle."