Lewis is making his second start against the Padres this season. He allowed three runs in 7 1/3 innings in a 6-5 loss on July 11. Lewis, who is going for a career high 15th win, is 6-2 with a 3.57 ERA in eight starts since the All-Star break.
Ross struck out nine in 6 1/3 innings in picking up a win over the Nationals the last time out, allowing four runs. His bullpen allowed three inherited runs to score in his last inning.