He sustained the injury on a first-down run from the Minnesota 20-yard line in the third quarter with the 49ers leading, 31-26. 49ers defensive lineman Kevin Givens tackled him behind the line of scrimmage and forced a fumble that San Francisco recovered.
Cook remained on the field as players from both teams and medical staff surrounded him. He was eventually able to stand up and get on a medical cart on his own.
The 49ers recovered Cook's fumble and scored a field goal to extend their lead to 34-26, which held up as the game's final margin.