"I'm not going to say one way or the other," Piniella said. "This could be more than a one-day thing, yeah."
Mike Fontenot, who is batting .337, started in place of Theriot and batted fifth on Monday in the opener of a three-game series against the Pittsburgh Pirates. He went 0-for-4 in the Cubs' 2-1 loss. Theriot came on defensively in the eighth inning, and then struck out in the ninth.
"Obviously you want to be in there playing, but you know I can play other spots as well," Theriot said after the game on Monday. "We'll just have to wait and see what happens. The main thing is winning ball games and hopefully we can start doing that."
Theriot's slump has been so significant that Piniella had his numbers ready to recite.
"One walk in one month," Piniella said of Theriot, who entered Monday batting .286 after staying over .300 for most of the season. "That's kind of hard to do."
Piniella was asked if he and the Cubs' staff have talked to Theriot about his lack of patience at the plate.
"We've talked to him about it," Piniella said. "He's had one extra-base hit the whole month. We'll see, we'll see."
Theriot was asked if he thought he was being singled out for his poor output in May, even when some of his teammates are struggling offensively.
"I don't think [Piniella] is singling me out," Theriot said. "I don't think he's taking me out. I have more at-bats than anyone on the team. I don't think that's it at all. Mike is swinging the bat well, and he might want to get him some at-bats."
Theriot was 5-for-35 (.143 average) in his past eight games entering Monday. He reached his high mark of .357 on May 4 but has since gone downhill. Since moving to second base on May 7 to accommodate rookie shortstop Starlin Castro, Theriot was batting .205 with a .225 slugging percentage, two RBIs and no walks or extra-base hits.
Even with his struggles, Theriot still is fourth in the National League with 59 hits.
"I like the energy he brings," Piniella said. "I like the way he plays baseball, but unfortunately for us what we need here is offense."
Bruce Levine covers baseball for ESPN 1000 and ESPNChicago.com.