MILWAUKEE -- The Cardinals' rotation for the final four weeks of the regular season is taking shape. It includes Kyle Lohse and John Smoltz, but not Mitchell Boggs.

Lohse is slated to return to the St. Louis starting five on Saturday at home against Atlanta. He'll displace the rookie Boggs, who moves to the bullpen following the best start of his young career. Smoltz, meanwhile, will take at least one more turn in the rotation, and it sounds like his starting job with the Redbirds is quite open-ended at this point.

"We've got it mapped out the last four weeks where our starters will be well taken care of," said manager Tony La Russa.

That comment indicates that the Cardinals intend to go with a five-man rotation over the closing weeks, which was no certainty. With an off-day in each of the final four weeks before the playoffs, St. Louis could come very close to using a four-man rotation while only spotting a fifth pitcher in now and then. It appears the Cards will not do that, though.

Still, that doesn't necessarily mean that Smoltz will start if and when the Cardinals make the playoffs. La Russa said he would have no hesitation to use Smoltz in the bullpen in October, even if he hadn't made a single relief appearance during the regular season.

"Every time he can start a game, he gains arm strength and sharpness," La Russa said. "We've got him tomorrow and he'll take the ball next time on his turn."

As for Lohse, he was listed as an available reliever on Monday and could be on call Tuesday as well. If he doesn't pitch in relief in the next couple of days, though, he'll throw a bullpen session to begin getting ready for a start over the weekend.

Lohse was activated from the disabled list on Sunday after missing 15 days due to a strained left groin.

"Just playing it by ear," Lohse said. "Take it as it comes."