Marlon Mack had a stellar year last season, rushing for over 1,000 yards. Unfortunately, he broke his hand and had to miss a few games. What was also unfortunate was his lack of help from the other members of the offense. The running game carried the team.
The same might happen next season too. Mack will have to be great again for this team to go places. What might help him is running more to the right side. The Colts ran to the left side way more than the right side last year, and it was very predictable.