Ryan Mathews allowed his fumble in Monday night's opener to disrupt his performance for the remainder of the game. "After that play, everything went downhill," Mathews said. "I wasn't even making reads. I was just taking the ball and running as hard as I could. The problem was that I wasn't running smart. I ignored my instincts and went away from everything I've been doing over the past few months." Before the second-quarter fumble, Mathews averaged 4.8 yards per carry. For the remainder of the game, the total dropped to 3.0. "At the time, it set me back," he said. "The fumble still bothers me, but I'm never going to get that play back. I have to move forward and try to make big plays down the line. ... My coaches and my teammates came up and said that I can't have lapses like that. It has a negative impact on the team, which is the last thing I want. "I have come up with a bad case of amnesia. When a bad play happens or I make a mistake, I have to let it go right away."