"Running back Darren McFadden, who left Sunday's loss to Kansas City in the first quarter and did not return, has a mid-foot sprain, Raiders coach Hue Jackson said.

"I'll know more as we go forward," Jackson said during his news conference Monday. "Obviously, we're going to have the foot looked at and make sure structurally that it's OK."

McFadden, the league's leading rusher through the first six weeks, played in the first two offensive series against the Chiefs before heading to the locker room. He emerged later on the sideline with his right foot heavily taped.

His absence was felt in the Raiders' 28-0 loss. McFadden has carried 113 times for 614 yards and four touchdowns and before Sunday was averaging an NFL-best 101.7 yards per game."