The Detroit Lions have wrapped up the 2017 season. Over the next several days, MLive.com will hand out reviews for each of the team's position groups.

Offensive line

Starters: Taylor Decker, Graham Glasgow, Travis Swanson, T.J. Lang, Rick Wagner

Backups: Joe Dahl, Don Barclay, Zac Kerin, Corey Robinson, Emmett Cleary, Brian Mihalik, Greg Robinson

Key stats: 47 sacks allowed, 32nd in run blocking and 21st in pass blocking per Football Outsiders, 10 starting lineup combinations

Kyle's grade: F

Nate's grade: D

Analysis: It is telling that the only assistant fired so far was offensive line coach Ron Prince. That unit was supposed to be a strength in 2017. In fact, it was among the worst in the league. It was straight garbage. Matthew Stafford was sacked 47 times, which was a career high and second most in the league. He was pressured on 36.5 percent of his dropbacks, which was 19th in the league. He had just 2.62 seconds to pass, also 19th.

This is an offense predicated on the pass. An offense that is built around the weapons-grade right arm of Matthew Stafford. And Detroit gave him bottom-third protection by almost every measure. That's a problem.

And they were even worse in the run game. Like, dead-last according to advanced metrics from Football Outsiders. There's a reason the Lions were dead-last in rushing, and dead-last in power rushing, and second-to-last in runs that didn't gain yardage at all. Detroit could use an upgrade in personnel in the backfield, of course, but the truth is those guys were slowed by some of the worst blocking in the league. And until that's sorted out, a new running back won't make that much of a difference.

Of course, the Lions also lost left tackle Decker to a torn labrum over the summer. And that was just the tip of the iceberg. Detroit sunk $19 million annually into Wagner and Lang, then lost them for a combined six games. Swanson sat out another five with various injuries, including another brain injury that ended another season prematurely.

The top offensive line started just two games intact. It was together for just 95 of Detroit's 980 offensive plays this season. Only Graham Glasgow played all 16 games. That would screw almost anybody up.

But the Lions' problems in protection and run blocking were more than just the injuries. Something was broken, and that's why the offensive line coach was dismissed along with Jim Caldwell. There will be new leadership in 2018, regardless of the fate of Jim Bob Cooter. And the importance of that hire simply cannot be understated. Because this team has too much invested into guys like Decker, Wagner and Lang to get these kinds of results. And way too much invested into Stafford to see him run for his life every Sunday.