LAKE FOREST, Ill. — The target will change, but not the quarterback — and at least not for now, the head coach.

As Chicago Bears coach Marc Trestman gets questioned more and more about his future with the team, a 41-28 loss Thursday night to the Dallas Cowboys left them without quarterback Jay Cutler’s chief target, Brandon Marshall.

On Friday, the team ruled him out of the next game on Dec. 15 at Soldier Field against the New Orleans Saints because of two fractured ribs and a lung injury suffered when Cowboys defensive back Barry Church tackled him on a reception in the second quarter.

Church’s knee struck Marshall in the right side. He went to the locker room and then to the hospital by ambulance.

“He’s a big guy and has taken a lot of crazy hits over the years,” Cutler said of Marshall. “He doesn’t stay down. So whenever he stays down you know something is seriously wrong. We’re all worried about him. He’s our guy, and hopefully he’ll get back sooner rather than later.”

Trestman said Friday that either Marquess Wilson or Josh Morgan would replace Marshall against New Orleans, but with the Bears only a win by a couple of teams from being eliminated, letting backup Jimmy Clausen play seems a logical possibility if the team wants to look to the future.

It won’t happen.

“Jay is our quarterback,” Trestman said. “If he’s available to play, he’s going to play. Jimmy is continuing to work in the offense and he practices and we certainly like having him on our football team, but as we get ready for New Orleans next week, Jay will get the reps and he’ll be playing.”

Cutler wasn’t the problem as much against Dallas as the lack of a running game was — for the second straight game. But Cutler admitted to frustration after a season that began with high expectations has now spiraled into one that has made the future uncertain.

“It’s got to be No. 1, I think,” Cutler said when asked where the disappointment of this year ranks. “Like (reporters) said, expectations coming into this one were extremely high and since the first game we haven’t done a good enough job, week in and week out. So it adds up.

“That being said, we can’t cash it in. We’ve got to still continue to build on this and find ways to get better and better each week.”

Cutler said he still has confidence in the coaching staff.

“I’ve been on teams where you went (out) on Sunday and you just knew the plan wasn’t going to be good enough,” Cutler said. “I’ve never lined up with this crew and felt this plan isn’t going to get it done, or we don’t have enough, or we’re outmatched, or we’re outschemed.

“That’s never been a thought of mine.”

Trestman received questions about whether he has concerns over job security after Thursday’s loss. He said Friday that there will be no changes this week on his coaching staff and his only concern beyond injuries is getting to work on a game plan for New Orleans.

Trestman said it’s easy to stay focused on the next game because he continues to receive support from management and ownership at Halas Hall.

“I don’t think it’s ever changed here — by all the key parties that you’re thinking about,” he told media members. “It’s been tremendously supportive, during the good weeks and bad weeks. And it’s been extremely consistent by everybody here.”

Trestman also said he does not see quit in the team despite a defense that surrendered a season-high 194 rushing yards to Dallas and ranks last in the league in points allowed, and an offense that has run for 50 total yards in two games.

“This team competes hard every day to get better, and they compete hard in the football game,” Trestman said. “It would be totally disrespecting our football team to think that they are not going out and competing as hard as they can.”

REPORT CARD VS. COWBOYS

PASSING OFFENSE: C-minus — When the game’s outcome still hadn’t been decided, the loss of wide receiver Brandon Marshall with a rib injury seemed to take the punch out of the attack. Jay Cutler was occasionally good at going downfield with a cover-2 beater along the edge so Alshon Jeffery could draw a pass interference penalty, and Cutler did his usual dumpoffs to Matt Forte and Martellus Bennett, but his 96.4 passer rating was largely the result of soft yardage against a zone protecting a big third-quarter lead. Forte had a huge fumble on a pass completion to start the second half, triggering the avalanche of Dallas points. The offensive line did an excellent job of protecting him considering the big deficit, and considering the Bears are going nowhere and had to pass, it’s more an indictment of Dallas’ pass rush and doesn’t say much for their chances to beat Philadelphia.

RUSHING OFFENSE: F — Just 15 rushing attempts doesn’t look like it on the surface, but an attempt was made to get the running game going. It was a misguided attempt, as the Bears continue to line up in formations that show they’re not serious about running. The 35 total yards was the result of an inability to get it blocked. The offensive line, and Michael Ola in particular at left guard, struggled to get a push or provide Forte any running room. The line deserves much of the blame this week as opposed to the game against Detroit when there was no attempt to establish the run. Blame here also must go to Forte. A handful of times in recent games he has been left alone off the edge cutting outside with only one defender to beat within a yard or two of the line of scrimmage and he can’t beat or run over that safety or linebacker.

PASS DEFENSE: B-minus — Tony Romo had too much time to throw, this much is true, but the reason for this was the defensive line was so preoccupied with stopping DeMarco Murray — or attempting to stop him anyway — that pressuring Romo became a luxury. Romo only beat them for 205 yards and the Cowboys did most of their passing damage with shorter passes when facing easily accomplished third-and-shorts because of the running game’s success on first and second down.

RUSH DEFENSE: F — The 194 yards allowed represented a season-worst effort. After stuffing Murray on the first play, the defensive front spent the rest of the night getting pushed back three yards. At times, it seemed Murray was slowed only because he was stopping at the line of scrimmage to decide which of the three or four big holes in front of him might provide the best chance to go all the way — if he’d simply hit the first one that opened he could have gained another 100 yards. Neither Jared Allen nor Willie Young were acquired to be run stuffers and that was obvious. Both got taken off the edge and Jonathan Bostic’s first official attempt to fill Lance Briggs’ run-stuffing role at weak-side linebacker proved a disaster as he got caught up in the wrong lane of responsibility or took poor tackling angles.

SPECIAL TEAMS: D-plus — In his first game, Jay Feely accomplished something injured kicker Robbie Gould never has — had an onside kick recovered. It was the first by the Bears since 2003 and actually provided some hope. Senorise Perry had a dumb penalty for stepping out of bounds, then coming in to down a punt when no one would have fielded the ball inside the 20 anyway. Generally, it was a do-nothing night on special teams, with a punt blocked, little return yardage and the Bears averaging their own 23 for a starting point to Dallas starting at its own 40.

COACHING: D-plus — Marc Trestman was asked for the second time about job security after this one, and several more are sure to follow. It might be a good idea in the future to avoid talking for a full week about how they need to run more because Dallas knew it was coming and a Cowboys defense that has struggled stopping the run managed to do it. The defensive approach was too conservative to try and avoid giving up a big gainer to Murray, but a few run-blitzes might have helped. More defensive pressure needed to be brought up the middle. Although Romo is good at rolling out and throwing, the Bears’ only defensive strength is their ends’ speed.