Marlon Mack

It's a bit difficult to know how the Colts value Marlon Mack, as they didn't attack any of the big-name running backs in free agency, but did draft two running backs in the first five rounds. He apparently played through a shoulder injury that required surgery all of last season, so it's possible that we haven't seen the best of Mack. The Colts offense could be a juggernaut if Andrew Luck is, in fact, healthy once again. This is one backfield to pay attention to in the preseason. Mack injured his hamstring during the first game, which is likely going to cost him a lot of practice reps in the new offense. He's among the riskiest RB3 picks in drafts.

Marlon Mack hurts hamstring in preseason opener

Marlon Mack is expected to miss a few weeks due to a hamstring strain, Jason La Canfora of CBS Sports reports.

Fantasy Impact

Mack limped off the field during the preseason game on Thursday. The injury isn't considered to be serious and the Colts are waiting for final confirmation that it is a strain. The 22-year-old running back should be ready for Game 1 and fantasy owners should keep an eye on updates.