The Chargers, whose backfield depth is one of their strengths, have added to their numbers at tailback.

The club has signed rookie running back Branden Oliver, an undrafted free agent from the University at Buffalo, the club said Wednesday.

The 5-foot-8, 203-pound Oliver rushed for 4,049 yards and 33 touchdowns in four seasons at Buffalo, racking up 1,535 yards and 15 TDs on 310 carries as a senior in 2013.

Ryan Mathews, Donald Brown and Danny Woodhead are the Chargers’ top three tailbacks. The club also drafted Arizona State’s Marion Grice in Round Six of the 2014 NFL Draft. In short, Oliver seems most likely to compete for one of the last backfield depth chart spots or a position on the practice squad.