Running back Marlon Mack of the Indianapolis Colts underwent an MRI exam for what the team believes is a strained hamstring, CBS Sports reported on Friday.
The report says the Colts anticipate that Mack will be out for a few weeks.
Mack grabbed his left hamstring after making a five-yard run with three minutes remaining in the first quarter of Thursday night's preseason opener against the Seattle Seahawks. He finished with four carries for nine yards.
Mack, a fourth-round pick (No. 143 overall) by the Colts out of South Florida in the 2017 NFL Draft, rushed for 358 yards and three touchdowns on 93 carries as a rookie last season, and also caught 21 passes for 225 yards and a score.