Marc Sessler ranked the NFL's deepest backfields earlier this week. Since it's July 11, and the website is clearly out of ideas, let's take a look at the thinnest backfields out there too.
This isn't a list of the running back groups that have lost the most weight this offseason. What teams are an injury away from real trouble?
1. Tampa Bay Buccaneers: Losing Doug Martin would be devastating for the Bucs' offense. It's a steep drop to Brian Leonard and Mike James on the depth chart. Tampa should look to add another body.
2. Jacksonville Jaguars: Maurice Jones-Drew is a shiny name at the top of the depth chart, but he has serious injury concerns coming into the season. If MJD gets hurt or needs a spell, journeyman Justin Forsett is next in line. Rookie Denard Robinson is listed as an "offensive weapon" but will probably play receiver more. Jordan Todman and Jonathan Grimes fill out the depth chart. There's a lot of hoping here, and not a great plan.
3. Kansas City Chiefs:Andy Reid has one of the best running backs in the league with Jamaal Charles. Reid has one of the shakiest situations behind his starter. Rookie Knile Davis looked like a workout wonder with suspect instincts. Next up: Shaun Draughn and Cyrus Gray. This running game could collapse if Charles was hurt.
4. Oakland Raiders: Any team starting Darren McFadden should assume that their backup is going to start multiple games. The candidates in Oakland: Rookie Latavius Murray, deposed former Jaguar Rashad Jennings, and underrated second-year pro Jeremy Stewart. It's never good when a team is counting on a sixth-round draft pick to matter.
5. St. Louis Rams: Chris Wesseling loves him some Isaiah Pead. There's potential there. Daryl Richardson looks like a fine third-down back. There is buzz about fifth-round draft pick Zac Stacy, but he was a fifth-round choice. Add it all up, and the group is still trailing behind the pack.
6. New York Giants:David Wilson is a very promising starter, but he's unproven in the role. Everyone assumes Andre Brown is a great second option because of one Thursday night performance against the Carolina Panthers. Brown was a great story, but there's usually a reason four teams let a player go. A veteran addition would not surprise.
7. Miami Dolphins: Lamar Miller is one of our upcoming "Making the Leap" candidates, but we have no faith in Daniel Thomas as a primary backup and the team only has fifth-round rookie running back Mike Gillislee behind him. I'm a huge Ryan Tannehill fan, but there's a risk the team will put too much on his plate.
Follow Gregg Rosenthal on Twitter @greggrosenthal.