It's tough to know whether bad sod influenced either injury or to what degree.
The Washington Redskins apparently don't want to take chances. The team plans to upgrade the surface at FedEx Field in June and replace it after a Nov. 3 game against San Diego -- three weeks before the San Francisco 49ers visit for a Monday night game Nov. 25.
The Redskins led the NFL in rushing yards at home last season. They ranked second in rushing yards on the road. It's tough to say a poor surface prevented their offense from gaining traction. But with Griffin's knee buckling awkwardly on uncertain footing last season, the Redskins needed to improve the surface.
The 49ers and Arizona Cardinals have each played a league-low five road games on natural grass over the past two seasons. The 49ers have gone 4-1 in those games, outscoring opponents by a combined 36 points.