The Lions offense continues to hum along, but there is trouble brewing on the other side of the ball.

The Detroit Lions clawed their way to a third straight win on Sunday against the Chicago Bears. It wasn’t pretty, and as a result, neither is their subsequent report card. There were some good performances here and there, but Detroit needs a much better showing on Thursday, when they’ll be playing the first-place Minnesota Vikings.

Here’s how Detroit graded out on Sunday:

Quarterbacks: B+

Matthew Stafford had another slow start here and another bad turnover that quickly dug the team into another 10-0 hole. But Stafford almost immediately made amends by having one of the best quarters of his entire career:

Overall, it wasn’t Stafford’s best day. He was a bit inaccurate at times, and that careless fumble he had was what got Detroit in trouble against the Saints. Still, Stafford was brilliant on the deep ball and has shown some incredible touch at times. November is his month.

Running backs: C-

The Lions run game was awful again, but I have a hard time holding it against the Lions’ Running backs, especially when they both made plays. For the second straight week, Theo Riddick actually looked like a pretty competent running back. In fact, check this out:

Past 4 games:

Ameer Abdullah: 54 rushes, 149 yards (2.76 YPC)
Theo Riddick: 22 rushes, 102 yards (4.64 YPC)

I’m not advocating for any change in running back here, but this is interesting nonetheless.

Anyways, the backs aren’t making enough plays, but they’re hardly the biggest problem in the running game.

Tight ends: C+

The tight ends didn’t do anything noticeably objectionable when blocking. Darren Fells and Eric Ebron combined for five catches and 58 yards. With Danny Trevathan out of the game, the middle of the field was open for the Lions to exploit.

The tight ends didn’t blow up this matchup, but they made just enough plays to help this offense when they needed a big play. None were bigger than Ebron’s 26-yard grab that got Detroit into field goal range for the game-winning score.

Wide receivers: B+

Marvin Jones Jr., TJ Jones and Kenny Golladay all made a fair share of big plays in this game. Like I said earlier, the deep ball is back in Detroit, and a lot of that is due to great play from the wide receivers. I can’t stop watching Marvin Jones’ perfect double move on his 28-yard touchdown catch. So let’s watch it some more:

But Kenny Golladay had a devastating drop on the Lions’ final drive and a tough offensive pass interference penalty earlier in the game.

It wasn’t a perfect day from the Lions’ wide receiver corps, but it was definitely above average.

Offensive line: C-

This game started with Matthew Stafford getting beat the hell up and Detroit having no running game to speak of. While the latter continued throughout the entire game, the Lions’ pass protection eventually settled in, and we saw, albeit briefly, what can happen when Matthew Stafford has a clean pocket. Answer: He destroys all humans.

Expectations were pretty high considering this was the first game the entire starting offensive line played together in 2017, but it was unrealistic to expect everything to click in one game. But the weak spots on the line were a bit surprising. I though T.J. Lang and Rick Wagner really struggled in this game, ceding both quarterback pressures and gap-shooters in the run game.

The Bears’ front-seven is good, but the Lions face an even bigger challenge against the Vikings. They need to be better on Thursday.

Defensive line: F-

On one running play, Akeem Spence drove the offensive lineman into the backfield and made a tackle for loss. That is the only good thing I’ll be saying about the defensive line.

Detroit’s front four was an absolute disaster on Sunday. Earlier in the week, I wrote about how the Lions’ defensive end rotation is a mess, and Detroit proved me right against the Bears. Anthony Zettel and Jeremiah Valoaga were horrible both in the running and passing games. They were extremely susceptible to misdirection and completely failed to hold the edge in the running game.

As for pass rush, you may want to take a seat before you read what I’m about to show you:

The Lions’ CB5 had more pressures than anyone on the defensive line.

A week ago, we were all ready to give up Ezekiel Ansah for the rest of the year. Now, I want him back in the lineup as soon as possible.

Also, Cornelius Washington... HOW DO YOU NOT BRING DOWN MITCHELL TRUBISKY ON THAT FOURTH DOWN PLAY? YOU HAD A CHANCE TO STICK IT TO YOUR FORMER TEAM AND YOU BLEW IT!

Linebackers: D-

It’s time to start worrying about Jarrad Davis. I’m not talking about his long-term prospect; I’m willing to withhold judgment on Davis’ potential career trajectory until at least halfway through his second season.

However, I’m not so sure we can expect Davis to look much better for the rest of the year. He’s repeating the same mistakes and not showing much of any week-to-week improvement. We’re talking missed tackles, poor coverage on tight ends and a general look of confusion from Davis.

I thought Tahir Whitehead was a little better, and he’s the reason this isn’t another F, but he also fell victim to a few missed tackles.

Secondary: A-

It’s clear the strength of this defense comes from the defensive backs, and that was the case again on Sunday. Darius Slay had an impressive day, yet again. Detroit only gave up 179 passing yards on the day for a mere 6.0 yards per attempt. Many of those yards were eaten up by running backs and tight ends, because Detroit’s coverage on wide receivers was so tight.

Heck, even DJ Hayden picked up a scoop-and-score on a fluky Mitchell Trubisky fumble.

Special Teams: A

Matt. Freakin’. Prater. His 52-yard game-winning field goal was thing of beauty. In the cold, in the wind, after missing several field goal in warmups, Matt Prater drilled the ball with a trajectory that gave viewers no doubt it would be good from the moment it left his foot.

Elsewhere, Sam Martin dropped three of four punts within the 20-yard line, including one that pinned Chicago at their own 3-yard line.

It wasn’t Jamal Agnew’s best game, as he bobbled a few returns, but in the end, he didn’t turn it over. No harm, no foul.

Coaching: C

I have no gameday complaints or praises from Jim Caldwell’s in-game management. It wasn’t a tough day for decisions regarding time management, challenges or fourth down decisions. So let’s talk about the coordinators instead.

I thought this was another good game from offensive coordinator Jim Bob Cooter. Every week since the Steelers game, we have seen a new offensive play, and it has almost always been successful. The play-action play that turned into the Marvin Jones touchdown was well-designed, as was the 2-yard touchdown toss to Ameer Abdullah. Slowly but surely, Cooter is earning some trust back.

On the other hand, Teryl Austin seems to go through these embarrassingly bad stretches every year. Granted, he’s not dealing with the best personnel up front, but there was one, clear goal in this game: stop the Bears’ running game. 30 rushes and 222 yards later, it became pretty clear Austin’s gameplan did not effectively stop the run.

Again, it’s hard to put a ton of blame on Austin when his players are clearly not executing well, but it’s his job to get the best out of his players, and he didn’t on Sunday.