Colts' Mack week to week with hamstring injury
Andy Lyons / Getty Images Sport / Getty
Marlon Mack is going to need some time off after hurting his hamstring in the preseason opener Thursday night against the Seattle Seahawks.
The Indianapolis Colts running back is listed as week to week with the injury.
Mack rushed four times for 9 yards while grabbing two receptions for 23 yards during the Colts' 19-17 victory.
The 22-year-old was selected 143rd overall in the fourth round of the 2017 draft and finished his rookie year with three rushing touchdowns and 358 yards on the ground on 93 carries.
Indianapolis has also ruled wide receiver Deon Cain out for the 2018 season with a torn ACL suffered against Seattle. Cain was taken in the sixth round out of Clemson in April's draft.