CHICAGO -- Jim Thome missed his second consecutive game on Friday, this time due to stiffness in his back.

The left-handed slugger was left on the bench Thursday instead of facing Tigers starter Kenny Rogers, against whom Thome is 9-for-49 lifetime. Facing a lefty again Friday in Colorado's Jeff Francis, White Sox manager Ozzie Guillen decided to give Thome an additional day of rest.

Thome told Guillen he is OK to play Saturday, but Guillen may still let him rest his back for another game, usually giving his players with even a minor malady that extra day for precautionary measures. If Thome sits through the weekend, he would get a five-day break, as the White Sox have an off-day on Monday.

"We'll see how he feels," Guillen said. "I don't mind giving him another day. He's gotta feel real good to make him play [against a lefty]."

The White Sox will face yet another southpaw Saturday, this time being Jorge De La Rosa. "I'd rather give him one more day and let him rest," Guillen added. "He was fine; he told me he could play. We'll see how he feels."