Three of those have resulted in turnovers.
He also dropped two passes in Carolina's 20-7 loss to the Tampa Bay Buccaneers. Foster finished the game with 64 yards on 13 carries and caught three passes for 17 yards.
"Anytime we put the ball on the ground, it's a concern," Fox said.
Foster's third lost fumble of the season came at the Carolina 29-yard line in the third quarter after picking up nine yards on a third-and-10 draw play. Foster's backup, DeAngelo Williams, got only two carries for five yards and caught three passes for 37 yards, including a 24-yard touchdown with 23 seconds left in the game.
Fumbling Foster Frustrates Fox
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