Manager Tony La Russa said Friday that Ludwick told him he thought he'd be available to pinch-hit that night against the Milwaukee Brewers. Ludwick instead missed his ninth start in 10 games and general manager John Mozeliak said there was a "high probability" that Ludwick would go on the DL in a move backdated to last Friday.
Ludwick said he felt the calf grab but didn't think it put him back at "square one."
"My understanding is I'll probably, likely, go on the DL," Ludwick said. "I'm glad I didn't go out there, though, and do it during the game. At least it's retroactive, so that's kind of nice."
La Russa had been thinking Ludwick would return by Tuesday at the latest after an off-day and perhaps could have played this weekend. Ludwick was batting .273 with 11 homers and 42 RBIs, third-best on the team.
"He tried to step it up a little bit and he tweaked something, so I'm certain we're going to disable him," La Russa said. "He said he tried to go just a little harder, he thought that he could, and felt something."
La Russa wants Ludwick to take his time returning to avoid another setback.
"Let's just get him well and see him after the [All-Star] break," he said.
The Cardinals played a man short Friday and were expected to add a minor league outfielder in place of Ludwick.
In a separate move, the Cardinals returned to a 12-man pitching staff by recalling infielder Tyler Greene from Triple-A Memphis and optioning right-handed reliever Fernando Salas to Memphis. Greene was in the lineup batting ninth and playing second.
Greene played primarily shortstop at Memphis earlier this year but could be used at three infield spots. He batted .291 in 62 games at Memphis and hit .231 in 10 games for the Cardinals earlier in the season.
"I'm just going to go out there, play as hard as I can and let it happen," Greene said.
Penny, also expected back after the break, is scheduled to throw a second bullpen session Saturday and either a simulated game or batting practice Tuesday in Colorado. He's been out since May 22 with an upper back injury.