CHICAGO -- Frustration boiled over inside the Chicago Bears' locker room Sunday just minutes after the team fell 27-14 at Soldier Field to the Miami Dolphins. Yelling could be heard from outside the double doors, and a source said receiver Brandon Marshall called out quarterback Jay Cutler.

The source said there "are some very selfish individuals in the locker room." But it's not out of the ordinary for Marshall to strongly voice his opinion to Cutler, as the two are close friends off the field.

Marshall, meanwhile, didn't deny there was friction in the aftermath of the game.

"We lost, there should be a lot of frustration," Marshall said. "You should hear frustration. We're 3-4. Yeah, this means everything to a lot of guys in this locker room. This means a lot."

Although it was believed that Marshall also yelled at kicker Robbie Gould, the receiver declined to answer when specifically asked.

"OK, were you in here?" Marshall asked. "Were you in this locker room? This is a team matter. That has nothing to do with you. There's a lot of guys this means a lot to. We're 3-4. We need to play better. That's unacceptable. That's unacceptable. Unacceptable; shouldn't have lost today, shouldn't be 3-4. [The] offense [has] got to play better. It's as simple as that."

Cutler threw an interception and was credited for two fumbles (one came as the result of Ka'Deem Carey dropping a lateral) as the Dolphins scored 10 points off two of the quarterback's turnovers.

In all four of the team's losses this season, Cutler turned over the ball multiple times. Yet in the team's three victories, Cutler didn't commit a turnover.

Chicago's opponents have scored a total of 37 points off Cutler's turnovers alone this season.

"Same mistakes, same mistakes, same mistakes," Marshall said. "We've got to protect the football. We've got to protect the football. We've got to execute the game plan. We've got to adjust when things don't go as we saw on the film. We've got Alshon Jeffery, Martellus Bennett, Matt Forte. We've got a stud offensive line. We've got a great, great group of guys, and this is unacceptable. What did we put up, 14 points? Was it 14 points? That's unacceptable."

Cutler passed for 190 yards and a touchdown but was sacked three times and finished with a passer rating of 74.4. Marshall caught six passes for 48 yards on 10 targets, and the source said the receiver was unhappy with the number of balls thrown his way.

Cutler admitted the postgame locker room "was emotional," adding that the "guys are really down on this one, myself included."

Bears coach Marc Trestman said he "told our team today was an unacceptable performance" but took accountability for what transpired.

Marshall, meanwhile, stressed that the club's underachieving offense hasn't lost confidence.

"My confidence is still there. Alshon Jeffery's confidence is still there. Martellus Bennett's confidence is there," Marshall said.

What about Cutler?

"Yeah, Jay's a gunslinger," Marshall said. "Jay's our guy. Jay's our leader."