ST. LOUIS -- The Cardinals are once again in need of a fifth starter.

Manager Mike Shildt said the club will wait until later in the week to name its choice, though the list of candidates does not include Genesis Cabrera, who was optioned back to Triple-A Memphis following his 4 2/3-inning performance on Tuesday. Right-hander Ryan Helsley takes Cabrera’s place on the active roster and will be immediately available out of the Cardinals’ bullpen.

The Cardinals could go in one of two directions to fill that rotation vacancy. Michael Wacha, who made nine starts before being moved to the bullpen late last month, is a confirmed candidate. His scoreless 2 1/3-inning performance behind Cabrera on Tuesday has given the organization some hope that Wacha has resynced his mechanics. An uptick in velocity was also encouraging for a pitcher who had a 5.59 ERA as a starter earlier this season.

Or the organization could give the chance to someone in Memphis’ rotation. Daniel Ponce de Leon has already made one spot start this season. Jake Woodford and Alex Reyes would also be rested enough to take the ball when that fifth spot turns back up on Monday. Reyes seems an unlikely choice given that he was just stung for seven runs and three home runs in his return from a left pinkie injury. He’s also still limited at the plate.

Because of Wednesday’s postponement, the Cardinals won’t need their fifth starter to appear in this weekend’s series against the Cubs. Instead, he’ll start the series opener in Miami. 

A hint as to which direction the Cardinals are leaning should come on Thursday, as that’s the day Ponce de Leon is scheduled to make his next appearance for Memphis.

As for Cabrera, he returns to the Minors with homework, most notably correcting whatever "tell" the Cardinals believe the Reds picked up Tuesday.

“I think it was pretty apparent that they had something on Genesis,” Shildt said. “He has too good of stuff not to have a swing-and-miss or a strikeout. It’s something we knew and tried to clean up in real time here.”

After generating five swinging strikes in his 53-pitch Major League debut against the Phillies, Cabrera did not get the Reds to whiff at any one of his 95 pitches. He was knocked for eight hits and four runs (three earned).

“Listen, he’s got plus stuff,” Shildt said of the pitcher who ranks eighth on the MLB Pipeline’s organizational prospect list. “If you’re calling a pitch and a guy knows what’s coming, it speaks to the quality of pitch that they still don’t do a lot of consistent damage to it.

“This guy is going to help us, for sure, moving forward. I believe it will be this year. He has to go to Memphis and still evolve his craft.”