The good: The good is rather limited here when we're talking about the worst rushing offense in the NFL this season.

The Lions never got their running game going, which had to be rather disappointing for offensive coordinator Jim Bob Cooter, who admittedly spent a lot of time this offseason trying to develop and improve that aspect of his offense.

Theo Riddick caught 53 passes for 444 yards and two touchdowns, marking the third-straight season in which he's caught at least 50 passes out of the backfield.

Undrafted rookie free agent Tion Green got an opportunity to play late in the season, and made the most of it. He showed he could run with some power. Green could get an opportunity this offseason to show how he can develop heading into year two.

The bad: Let's start with the fact that Detroit finished last running the football this season at 76.3 yards per game. The next worst rushing team, the Cincinnati Bengals, averaged 85.4 yards per game.

Only 36.4 percent of Detroit's 363 rushing plays gained at least four yards. Only the New York Jets (36.3) had a lower percentage. Detroit's 61 runs for negative yards were the 10th most in the NFL.

There was also a severe lack of big plays in the run game for the Lions. Detroit ranked 29th in the total amount of runs that gained 10-plus yards (34) and 26th in 20-plus-yard runs (7).

Third-year running back Ameer Abdullah led the Lions with 552 rushing yards, which ranked 36th in the NFL. Abdullah started the season carrying the load for Detroit's run game, but was given a decreased role late in the year after averaging only 3.3 yards per attempt on 165 carries.

The offensive line doesn't get a pass here. Injuries, and the fact the Lions started 10 different offensive line combinations on the year, played a role in the lack of a run game. There simply weren't enough holes for backs to run through, and when the team is devoid of a back with a combination of size, speed and vision, there's not a lot of hay to be made in the run game when the offensive line doesn't provide those running lanes.

Key stat: The Lions averaged 3.88 yards per rush when running left. That number dipped to 3.13 yards per attempt when running right. When the Lions ran up the middle, they averaged just 2.83 yards per attempt, per STATS INC.

Free agents: Mike James (unrestricted) and Zach Zenner (restricted)

Abdullah, Riddick, Green, and Dwayne Washington are all under contract for next season, but expect a shakeup in Detroit's backfield next season. Don't be surprised if general manager Bob Quinn brings in new blood via free agency and the NFL Draft.

Riddick is probably the only back right now guaranteed a spot in the rotation next season, based off what he brings to the table in the passing game as a third-down back.

Draft: Last year was one of the best running back draft classes in the last decade, and early indications are that this year's class could be just as strong.

Kareem Hunt, Leonard Fournette, Alvin Kamara and Christian McCaffrey made instant impacts as rookies this season.

The 2018 class of running backs looks to have players who can also make an instant impact. It's headlined by Penn State's Saquon Barkley, who will likely be a top five pick.

But there's plenty of talent and depth behind Barkley in the likes of Derrius Guice (LSU), Bryce Love* (Stanford), Kerryon Johnson (Auburn), Ronald Jones II (USC), Nick Chubb (Georgia), Sony Michel (Georgia), Rashaad Penny (San Diego State), Damien Harris* (Alabama), Royce Freeman (Oregon) and Bo Scarbrough* (Alabama).

*underclassman who haven't official declared for draft yet (Jan. 15 deadline)

MVP: Riddick's ability to run routes like a receiver, catch the football out of the backfield and make people miss in the open field makes a defensive coordinator have to plan for him throughout the week.

Riddick and quarterback Matthew Stafford are so good with those option routes out of the backfield. They have a terrific feel for one another in the pass game, and that will only continue to grow moving forward.

Most improved: This probably has to go to Green if we consider how much he improved throughout the course of the season. He made the 53-man roster out of training camp, but was inactive on gamedays early on this season. He developed in practice, and showed some good things. He made the most of the opportunity later in the year when he got a chance to play on Sunday and tote the rock.

Quotable: "I think our running backs, you know, they didn't perform as good as everyone thought," Quinn said after the season. I think that's the facts.

"But I think we have guys in that room that are tough guys, they're smart guys, they have skill. Will we add someone probably to that room? Absolutely. But that's how the NFL really rolls. Every year there's about 30 percent turnover on teams, so you're never going to have the same team year-to-year."