Montgomery is scheduled to undergo further testing after exiting Sunday's 20-6 win over the Buccaneers with a rib injury, Kyle Meinke of MLive.com reports.
Montgomery was injured when he landed hard on the field after being tackled in the second quarter. Initial X-rays on Montgomery's rib came back negative, but further tests are required to determine the precise nature and severity of his injury. With Jahmyr Gibbs (hamstring) also banged up and having missed the Lions' last two games, Craig Reynolds could be Detroit's lead back Week 7 against Baltimore if the top two options on the depth chart miss further game action.