The news of the injury was first reported by the Detroit Free Press.
The source added Worrilow is likely to miss at least this week's game against the Carolina Panthers and then go from there.
This isn't the first time Worrilow has dealt with injuries in his left knee. In 2015, he had to have his left knee drained after a game against Carolina and practiced on a limited basis after that.
Worrilow signed with Detroit in the offseason and has been a rotational linebacker with the Lions. After Jarrad Davis missed the past two weeks with a concussion and neck injury, Worrilow has played more defensive packages. He started both games for Detroit in Davis' absence and has six tackles.
He was injured on the first defensive play against the Vikings on Sunday and was carted off the field.