Lions coach Matt Patricia called it "short-term IR," leaving open the possibility he will return this season.
Flowers, 27, has 22 tackles, two sacks, two forced fumbles and a fumble recovery this season. Patricia said Sunday's injury was new and not cumulative from other games. Flowers previously had been dealing with a wrist injury.
Patricia did not have a clear update on receiver Kenny Golladay, who left Sunday's 41-21 loss in the first half with a hip injury and did not return. Patricia would not say whether Golladay, who missed two games this season with a hamstring injury, would be available Sunday against the Minnesota Vikings.
"I would say it's day-by-day and week-by-week, I would say that is true," Patricia said. "Obviously everybody is a little bit sore today from the game yesterday, it was a physical game and today guys are going through their medical checks and then we'll see how it looks tomorrow and see how it looks at the end of the week, really."
Golladay has 20 catches for 338 yards and two touchdowns this season in five games.