LAKE FOREST, Ill. -- Chicago Bears safety Chris Conte missed practice Monday as he goes through the NFL's return-to-play concussion protocol, while Jared Allen (shoulder), Eben Britton (hamstring), Kyle Fuller (ankle) and Isaiah Frey (hamstring) returned to workouts inside the Walter Payton Center as the team preps for the exhibition finale at Cleveland.
Conte suffered a concussion during the second half of the club's loss Friday at Seattle. It was his first live action since missing the entire offseason and much of training camp after undergoing offseason shoulder surgery.
Bears coach Marc Trestman declined to give a timeframe for Conte's return, citing the fluidity of the NFL's concussion protocol.
Asked about the severity of Conte's concussion, Trestman said, "I can't answer that. I can't. It's a day-to-day thing. He's going through the protocol. I saw him after the game, and he was in a good place. But obviously he's going through the protocol right now, so I don't have an answer to that question."
Conte's latest setback brings about another question as to whether he's done enough to earn a spot on the team's 53-man roster given his limited exposure in the evaluation process. The Bears opened up training camp with an open competition for both starting safety spots, and Conte -- given his experience -- seemed to be one of the favorites to win a job.
Bears defensive coordinator Mel Tucker liked what he saw from Conte against the Seahawks.
"I thought Chris played fast. He was aggressive. He made a nice play in the end zone. He was excited to be out there," Tucker said. "There was no hesitation with Chris in his reads and his progressions, and I thought that was positive. With the amount of evaluation time available, we felt like that was enough time to make a clean evaluation on him, and we don't feel differently."
Against the Seahawks, Conte was credited with one assisted tackle and a pass breakup when he laid a vicious hit on Luke Willson in the end zone to prevent what would have been a touchdown.
Although Britton, Fuller, and Frey returned to practice Monday along with receiver Chris Williams, Trestman was unsure of their availability for the exhibition finale, and called Fuller and Frey day-to-day. Right tackle Jordan Mills (foot) also took part in Monday's practice, but hasn't yet played in a preseason outing. Brian de la Puente (knee) was also held out of Monday's workout.
Conte, meanwhile, started training camp on the physically unable to perform list, and didn't take part in his first practice until Aug. 10.
Conte finished third in tackles last season (95), and tied for second with three interceptions. Conte struggled tremendously through the 2013 season, highlighted by him playing the wrong coverage on a late fourth quarter Randall Cobb touchdown in the team's Week 17 loss to the Green Bay Packers which knocked the Bears out of the playoffs.
Conte said the 2013 season led to "a lot of soul searching" in the offseason.
"It was a good time for me to get better in a lot of different areas," Conte said during training camp. "Hopefully I'm a better person and a better football player. I learned to keep people close to me that I care about and to always know the people that support me are the only people that really matter. I'm not even thinking about last season. I'm thinking about this year. I don't even know what happened last season."