With the Colts ending the tenure of Frank Gore this past week, the stars have aligned for rookie running back Marlon Mack to take over the starting position for the start of next season. But with Robert Turbin, Matt Jones and Josh Ferguson all under contract in 2018, I find it hard to believe that Chris Ballard and his staff feel secure with the depth at the position. Running back is the most dangerous position in football and one injury to Mack could have the Colts scrambling for answers.