On a team with three Pro Bowl defensive backs, there's not a lot of room for error among the backups. And perhaps with that challenge in mind, Robert Nelson is going all out this offseason.

The 25-year-old cornerback, who signed with the Cleveland Browns last year as an undrafted free agent, posted a video of himself pushing and pulling a small car. As if this unique form of strength training wasn't enough, Nelson is wearing an endurance mask that makes it feel as though he is training in altitude.

Sure, this is a smaller vehicle, but it's a car nonetheless. Plus it's a Mercedes, a fact that adds a certain prestige factor to Nelson's workout.

Nelson is going to have to have a stellar offseason in order to see the field in 2015. He's behind Joe Haden, Tramon Williams and Justin Gilbert on the depth chart. The Cleveand secondary was stellar in 2014, leading the league in opponents' QB passer rating (74.1), completion percentage (57.1) and passes defended (99).

More: J.J. Watt Can't Complete Jump Box, Takes Out Spotter On His Way Down