ST. LOUIS -- It has been one day at a time for Cardinals reliever Mike Mayers, who is finding his way back to the mound after a right lat strain put him on the injured list in the middle of April.

The good news, though, is the right-hander is ahead of schedule, manager Mike Shildt said Thursday.

Mayers will throw a bullpen session either Friday or Saturday and could be pitching somewhere in the system by the end of the month. Mayers had hoped to be back in the Cardinals’ bullpen shortly after the All-Star break.

“We don’t want to put a hard timetable on it,” Shildt said. “But it doesn’t seem to me to be unreasonable, the way he’s recovered. Everybody is tickled he’s this far ahead of where he might be based on what he had, but he’s not being rushed at all. Just recovering really well, being diligent. He’s in a really good spot.”

Mayers said he’s feeling more like himself as he’s gotten his range of motion back. He’s been throwing for three weeks and has eased back into a daily regimen with scheduled off days.

“It’s been a slow process, but I think I’m getting closer to the end,” Mayers said. “The big thing they’ve stressed to me is one day at a time. A setback is way bigger than trying to cut a corner here and there. I know my schedule like a day or two ahead, but other than that, I don’t know.”

Mayers, who is out of Minor League options, broke camp with the Major League team and made eight appearances before his injury. He held opponents to one run over his first 6 2/3 innings before being scored upon in his last two outings before the injury.

The strain happened on one pitch when he entered in the bottom of the sixth inning in the Cardinals’ 10-7 loss to the Brewers on April 15. He ended up allowing three runs on two hits and ballooning his then-2.35 ERA to 5.40.

“It felt like you wake up in the middle of the night and you get a cramp in your calf, but it was in my armpit,” Mayers said. “I thought, ‘Man, this feels weird,’ and I threw a couple more pitches, and the cramp kept getting bigger.”

That feeling has since disappeared, and Mayers has been able to focus on building his strength back to what it was at the start of the season.

Starting decision forthcoming

Wednesday’s rainout not only pushed back the starting pitchers, but also the Cardinals' decision on who will pitch Monday’s game against the Marlins in Miami. Shildt said he hopes to have a name by Friday.

Michael Wacha is still in the mix as an option, but there could be more of an opportunity to give a chance to someone in the Memphis rotation.

Daniel Ponce de Leon (4-4, 4.13 ERA) is scheduled to start Thursday’s game, which begins at 9:05 p.m. CT. But there’s a chance that he won’t go very far into the game.

“I don’t know,” Shildt said. “I think he’ll get a start, and [work] an inning or two. But I’m not sure.”

If Ponce de Leon does just go an inning or two, that could be an equivalent of a bullpen session for the right-hander, who has made successful spot starts before for the Cardinals. That would make him available to start on Monday.

Alex Reyes and Jake Woodford are scheduled to start Saturday and Sunday, respectively, for Triple-A Memphis.