Safety Chris Conte is not expected to play Thursday night because of the concussion he suffered vs. the Seahawks last Friday, the only game in which coaches can evaluate his play in his comeback from off-season shoulder surgery.
Final cuts down to 53 are due by 3 p.m. Saturday.
"That's not easy," coach Marc Trestman said. "We're going to have to make some decisions over the weekend, and they're not all based on just the facts. There's some feel to some of these things, how the team is going to be put together."
Ryan Mundy (strong) and Danny McCray (free) started each of the first three exhibition games. But with McCray (head laceration) and Conte out this week, it was rookie Brock Vereen joining McCray with the ones.
Defensive coordinator Mel Tucker was asked if Conte could still win the starting job.
"With the amount of evaluation time available," Tucker said, "we felt like that was enough time to make a clean evaluation on him, and we don't feel differently."
Tucker liked what he saw from Conte last Friday before he was injured, especially his hit that knocked tight end Luke Wilson out of the game and broke up what would have been a TD pass.
"I thought Chris played fast," Tucker said. "He was aggressive. He made a nice play in the end zone. There was no hesitation with Chris in his reads and his progressions."
Getting a long look:
Rookie quarterback David Fales, a sixth-round pick from San Jose State, will start Thursday night and could play the entire game.
Fales has thrown just 7 preseason passes, but coach Marc Trestman said his play in practice has been encouraging.
"He's extremely bright," Trestman said. "He understands the system in terms of our verbiage, how we get out of the huddle and get plays called and get out of plays. He's got very good feet, he's accurate, and he's not afraid to throw the football around and try to make plays.
"He's gotten a lot of work scout-team-wise and individual-wise. I'm excited to see what he can do. When we looked at him we saw that he's a very accurate passer, which is something that is hard to coach into a player. He's got some mobility."
Cornerback Isaiah Frey and guard James Brown were waived, leaving the Bears' roster at the required 75. Frey did not practice Tuesday because of soreness after returning to practice Monday from a hamstring injury.
In addition to safeties Ryan Mundy and Chris Conte, fullback Tony Fiammetta (hamstring) and guard-center Brian de la Puente (sprained knee) did not practice Tuesday.