Injured Chicago Bears quarterback Jay Cutler will miss at least the next four weeks of the season and Pro Bowl linebacker Lance Briggs will be out for around six weeks, staggering blows for a struggling team.

The Bears announced the news Monday, a day after Cutler suffered a muscle tear in his groin during a 45-41 loss to the Washington Redskins. Briggs left the game with a small fracture in his left shoulder. Neither player will need surgery.

"They're not done," coach Marc Trestman said. "They're going to be back."

Pro Bowl cornerback Charles Tillman also left the game with a knee injury as Chicago (4-3) lost for the third time in four games.

The Bears are off this week, but with the injuries mounting, their season could be slipping away from them. The defence has been hit particularly hard in recent weeks, and now, the offence is without its leader.

Cutler came up clutching the top of his left leg following a sack by 333-pound nose tackle Chris Baker with about 10 minutes left in the first half. He stayed down for a few minutes and eventually limped off the field.

"They said this is a minimum four weeks and then we'll evaluate it week to week," Trestman said. "Based on the history, I talked to the doctors this morning, of this injury, four weeks is a reasonable start and that it would be week to week."

Season not over

The Bears insisted Cutler will return this season.

"Unless there's a complication during his rehab, with the injury that he has that I'm certain he'll be back at some point," general manager Phil Emery said.

Josh McCown entered in the second quarter, seeing his first game action since the 2011 season. He completed 14 of 20 passes for 204 yards, including a seven-yard touchdown pass to Martellus Bennett that gave his team a 41-38 lead with 3:57 to play. McCown looked understandably rusty in his first few plays, but he put Chicago in position to win the shootout with the Redskins.

The Bears will need more of the same if they're going to have a chance of winning their next game at Green Bay on a Monday night following the bye, not to mention beating Detroit the following week.

They didn't fare well the last time they went an extended period without Cutler. After he broke his thumb two years ago, the Bears dropped five of six after a 7-3 start in a collapse that cost general manager Jerry Angelo his job.

Back then, Caleb Hanie struggled in a big way. The Bears then turned to McCown, who had been coaching high school football in North Carolina, late in the season. They have more weapons now with Brandon Marshall, Alshon Jeffery and Bennett, not to mention a rebuilt offensive line and a system that's geared more to quick, high-percentage passes than what they were running under Mike Martz.

"Especially in this league where the quarterback drives the ship, I don't know if you're ever ready to handle losing your starting quarterback," McCown said. "But I think the structure is in place and the emphasis has been put on individuals to do their job and do their part. If we continue to get that, and we felt like we got that yesterday, it allows the quarterback to step in there, whether it's Jay or myself, to function and play, because guys are going to be coached to be where they are supposed to be and do what they're supposed to do."

Palmer in backup role

With Cutler out, Chicago is bringing in Jordan Palmer to back up McCown. The Bears were one injury away from having receiver Earl Bennett line up behind centre because they only carry two quarterbacks.

Emery said that won't change.

He also said the Bears are looking to bring in a veteran with Briggs injured. And just for the record, Brian Urlacher is not a candidate.

Emery shot down that idea, pointing out that the former star middle linebacker filed his retirement papers before the season and received his termination pay.

He also said the Bears won't make a trade simply because of the injuries, even though they have some big holes to fill. They lost defensive tackle Henry Melton, his replacement, Nate Collins, and middle linebacker D.J. Williams to season-ending knee injuries. With Briggs out, rookie Jon Bostic or veteran James Anderson figure to call plays and rookie Khaseem Greene will likely get more playing time.

"We've worked trades here the last couple of weeks, we just haven't found the correct combination of value and player exchange," Emery said.