When the New York Giants sent in rookie running back Andre Williams for starter Rashad Jennings on Sunday night in their preseason opener, Jennings said he could see the whites of Williams' wide eyes. "I told him, 'Don't worry about it. As soon as you get hit, you realize it's just football,'" Jennings said. Williams did just fine. He carried the ball five times for 37 yards on the Giants' first touchdown drive of the game. On the play before he ran it in for a three-yard score, he rumbled 21 yards around the left side on a zone run. He showed power and speed and comfort with the offensive playbook. And while his performance came against a second-team Bills defensive line and he still has a ways to go before he can be trusted to contribute in the passing game, the fact that the Giants rotated Williams and Jennings in and out with their first-team offense indicates that he may be a big part of the initial plan.