Detroit Lions running back David Montgomery was forced to leave Sunday’s game against the Minnesota Vikings due to a knee injury.

Montgomery suffered the injury in the first quarter. He was targeted on third down when Minnesota led 10-0. Montgomery was slow to get up after the hit and needed the help of two trainers as he limped off the field.

The Lions initially considered Montgomery’s return questionable due to a knee injury. The exact nature of his injury was unclear.

In five games, Montgomery had 351 rushing yards and 94 receiving yards with six touchdowns. Before Sunday’s game against the Vikings, he had scored a touchdown in every game this season and was part of one of the best running teams in football alongside Jahmyr Gibbs. With Montgomery out, Gibbs becomes the clear leader of the Lions with Craig Reynolds as his replacement.

The Lions are coming off a game in Week 6 in which Pro Bowl pass rusher Aidan Hutchinson suffered a season-ending fractured tibia and fibula. Hutchinson, who had an NFL-best 7.5 sacks in five games, underwent season-ending surgery last week.

Detroit went 4-1 against the Vikings on Sunday to go 5-0 in the NFC North showdown.

This story will be updated as more information becomes available.