The Cubs wrapped up a three-game series against the Marlins on Wednesday before Thursday's off-day. By resting Theriot on Wednesday, he'll get two days.
The hamstring injury is not serious, team officials said. Theriot was batting .329 and has hit safely in 19 of his last 20 games, dating to April 21. He shifted from shortstop to second base last Friday to make room for rookie shortstop Starlin Castro.