Flash back to just one year ago. The Eagles were absolutely loaded at the running back position after signing reigning rushing champion DeMarco Murray and adding former first-rounder Ryan Mathews. The running game, easily the staple of Chip Kelly’s offense in the 2013 and 2014 season, was expected to be even more dynamic for a team that was considered a sleeper Super Bowl contender. Then everything went wrong for Kelly’s 2015…