Dan Campbell started to describe the coverage mistakes, then corrected himself.

“We had a couple of busts — we had more than a couple of busts — on the back end for touchdowns in the pass game that really hurt us.”

That admission captured the problem facing the Detroit Lions after Thursday’s 41–31 road loss to the Buffalo Bills. Campbell expected Josh Allen to make Detroit’s defense work. What he could not accept was how often the Lions made the assignment easier.

Buffalo finished with 446 total yards, including 203 on the ground. Allen accounted for five touchdowns, and Detroit surrendered 27 points before halftime.

Campbell’s explanation went beyond the difficulty of defending an elite quarterback. He identified missed assignments in coverage, poor containment up front and defenders occupying the wrong gaps against the run.

Campbell says Detroit helped Buffalo

The Lions knew the challenge entering Buffalo. Campbell said their execution fell below what that matchup required.

“Defensively, we knew it was a tall task, but we gave up too much. There were some things in there that we have to get cleaned up. You have to play your best ball to have a chance to reduce points against that team and that quarterback, and we did not do that. We had a hand in helping them out there a little bit, and it wasn’t good enough. It’s not good enough.”

The damage extended across the defense. Allen threw for 248 yards and three touchdowns while adding 69 rushing yards and two scores, as detailed in Reuters’ account of Buffalo’s victory.

Campbell’s distinction matters: Detroit can execute an assignment correctly and still lose a matchup against Allen. His concern was how often the Lions failed to complete the assignment itself.

Wrong gaps opened running lanes for James Cook

James Cook III rushed for 135 yards and a touchdown on 21 carries. Detroit had entered the game facing the possibility of a heavier workload for Buffalo’s lead back, and Campbell described breakdowns that helped him find room.

“We had a couple of busts in the run game too. Our fits, we’re fitting the wrong gap or not where we’re supposed to be. We’ve got two guys in one gap and Cook’s busting these runs.”

Two defenders reaching the same gap can leave another running lane unprotected. Campbell pointed directly to that failure to maintain responsibilities.

“That has nothing to do with them. That has to do with us. It was already a tall task, much less when you don’t handle your own business, your own job. So we’ll clean it up. Now we’ve got a minute to look at it and figure out where we can go here.”

His diagnosis echoed the accountability expressed by an emotional Jack Campbell after the loss.

Allen escaped situations Detroit needed to control

Dan Campbell also described opportunities when the Lions had created favorable down-and-distance situations, only to lose their advantage.

“Defensively, we give up too many explosives. Really, we had them pinned on a couple of these second-and-longs. We couldn’t keep them in the pocket. We’re running some games up front, and we get snatched inside and we can’t contain it, and he takes off. Those are some things we talked about. We knew we were going to need somebody to show up there, and we didn’t.”

That failure carried consequences beyond the yards Allen gained himself. Detroit wanted Buffalo facing difficult third downs. Instead, Campbell said the Bills repeatedly reached situations that left their quarterback sneak and push available.

“We talked about trying to play and keep them in second-and-long and make some of these third downs where it would favor us. Man, they had a ton of third-and-shorts. A lot of them. And that’s hard because they do a good job with that quarterback sneak and the quarterback push. So we didn’t make life easy on ourselves.”

An aggressive plan required better coordination

Campbell said Detroit deliberately chose a more aggressive approach against Allen. He believed sitting back in coverage carried its own considerable risk.

“Look, we wanted to be aggressive today too. If you just sit back there and play coverage on this guy, he’ll light you up. He’ll start throwing those bombs down the field, and you can die that death.”

The issue, in Campbell’s assessment, was making sure that approach was supported by coordinated execution.

“So we knew we were going to be a little more aggressive today. That can string you out, but it’s not so much that as it is, okay, if we are going to do that, let’s just make sure we’re all on the same page. That’s all.”

His comments left a clear priority for the defensive review: determine where communication and assignments broke down before deciding how much the approach itself needs to change.

“We’ve just got to clean up a lot. We’ve got to clean up a lot of things on defense right now, particularly in the back end.”

Campbell still sees a defense that can improve

Campbell stopped short of declaring that Thursday’s mistakes were identical to those from the opener against New Orleans. He said Buffalo attacked differently and that he needed to review the film before making that comparison.

He also maintained confidence in the defensive front’s ability to help stabilize the unit.

“Because that’s what we’re tasked with, man. I think this front — we’ve got some juice up front. I think we’ve got a mix of guys that can apply pressure, that can stop the run, and that relieves a lot of stress on your back end.”

That confidence now has to translate into more disciplined play. Campbell acknowledged the result while keeping the season’s early stage in perspective.

“Listen, it stings. Nobody likes it. Certainly, I don’t like losing. I don’t like losing like that. But I also know we just finished Week 2. We’re 1-1, and we’ve got a ton of room to grow. So that’s encouraging.”