"He just feels lousy," said manager Ron Washington. "He tried to move around and do something, but it's not necessary for me to run him out there. We'll give him today off and hopefully he'll feel better [Saturday]."
Napoli was originally listed in the lineup, batting eighth and playing catcher. But he was scratched shortly after the initial lineup was posted.
He is batting .130 with 15 strikeouts in his last nine games, recording at least one strikeout in each of them. Napoli has hit seven home runs, but none since April 25. He had started in 35 of the team's 45 games -- 24 of them at catcher, 10 at first base and one at designated hitter.