ST. LOUIS -- Two days after Cardinals manager Mike Shildt acknowledged the need to consider changes for a team stuck in a month-long rut, he made some.

His first tweak was in the lineup, where Dexter Fowler moved to the leadoff spot and Matt Carpenter dropped to fifth for Friday’s series opener against the Braves. The other was with Michael Wacha, who is shifting out of the rotation and into the bullpen indefinitely.

The Cardinals will summon a fifth starter from Triple-A Memphis -- likely Daniel Ponce de Leon or Jake Woodford -- to start in Wacha’s place on Wednesday.

“Speaking to Michael, clearly a tough decision,” said Shildt, whose club had lost 14 of 19 games entering Friday since a 20-10 start. “We can’t be naïve to the fact that it’s a result-oriented business, and the timing of him pitching better but being on a string of inconsistent outings affected the decision. I think there’s a route back for him [into the rotation], but he’s got to go get some of the things we talked about more consistent.”

That checklist starts with fastball command and pitch selection. The Cardinals are also hopeful that pitching in shorter stints may generate a velocity boost for the right-hander. Two years after boasting an average fastball velocity of 95.1 mph, Wacha is averaging 92.4 mph on that pitch over nine starts. He has maintained that the dip is not the byproduct of any physical ailment, which only makes his results more perplexing.

The Cardinals’ patience with Wacha’s ragged year hit a breaking point Wednesday, when he allowed seven runs (six earned) over 4 2/3 innings vs. the Royals. That pushed his WHIP to 1.69 and his ERA to 5.59. Wacha’s walk rate (5.6 per nine innings) and home run rate (1.7 per nine innings) are at career highs.

“Unfortunately, in this game, you’re always left with having to make some tough decisions,” president of baseball operations John Mozeliak said. “I think everybody that’s standing in front of me would agree that May hasn’t gone as planned. And not making a decision or change probably isn’t the best idea."

Wacha, who is due to be a free agent at the end of the season, will be available out of the bullpen beginning on Saturday. Who will take his place in the rotation remains undetermined. It won’t be Alex Reyes, who still hasn’t been cleared to hit, or Austin Gomber, who isn’t expected back on the mound for Triple-A Memphis for about another week. Gomber has been nursing a left biceps injury since his May 13 start.

That leaves Ponce de Leon or Woodford as the leading candidates. In a spot start for the Cardinals on April 23, Ponce de Leon scattered two hits and allowed one run over five innings against the Brewers. He last pitched on Wednesday, going five scoreless innings for Memphis.

Woodford isn’t on the team’s 40-man roster, but he’s garnered plenty of attention with a stellar start to the Triple-A season. He leads all of Memphis’ starters with a 2.44 ERA.

Reyes on the mend

Making his first Minor League start since fracturing his left pinkie finger on April 25, Reyes threw 70 pitches (40 strikes) over five innings for Class A Advanced Palm Beach on Thursday. Reyes allowed one run on two hits and a pair of walks while striking out six.

“Stuff looked great,” Mozeliak said. “I don’t feel like we took a major step back [while being sidelined]. Now, we just have to get him into games.”

The Cardinals will have Reyes pitch once more for Palm Beach before being reevaluated. Once Reyes receives clearance to hit, he’ll return to the Memphis rotation. The club will not bring Reyes up to St. Louis until he has shown he’s able to comfortably swing a bat.

Worth noting

• Major League Baseball announced that Jason Isringhausen will serve as the Cardinals' representative at the upcoming MLB Draft. Isringhausen, the franchise’s all-time saves leader, was a 44th-round pick of the Mets in 1991.

• Triple-A first baseman/outfielder Rangel Ravelo extended his hitting streak to 18 games in Memphis’ loss to Nashville on Thursday. Ravelo is two games shy of matching Adam Kennedy’s franchise-best 20-game hitting streak.

• Ryan Helsley, optioned back to Triple-A on Thursday, is likely to continue pitching out of the bullpen, Mozeliak confirmed. The organization will prioritize multiple-inning appearances for the right-hander.