CHICAGO -- Jim Thome was not in the starting lineup for the third straight game Saturday due to stiffness in his back, but he also was available to pinch-hit and is expected to be back in his usual starting role for Sunday's series finale with the Rockies.

Facing a series of left-handed pitchers over the past three games -- Kenny Rogers, Jeff Francis and Jorge De La Rosa -- White Sox manager Ozzie Guillen felt it best to leave Thome on the bench to rest his back, rather than risk further injury.

"Thome is feeling better," Guillen said. "He talked to us about it. I am going to give him another day, just to be sure we're on the right track. Hopefully, I don't have to use him [Saturday]. If we need him, we're going to, but hopefully we don't. Last night, we could have used him, and hopefully, he'll be better tomorrow against a right-handed pitcher."

When Interleague Play takes the White Sox to National League parks as soon as next weekend, Guillen will use Thome in a limited role to protect him from the aches and pains of fielding a position.

"We planned that he will be available to pinch-hit. I try to stay away from him as much as I can at first base," Guillen said. "I have [Nick] Swisher who can play first, too. Last year, we played [Thome] a little bit, and all of a sudden, it took like two weeks to recover."