The Cardinals placed Ludwick on the 15-day disabled list Wednesday because of the injury and recalled outfielder Nick Stavinoha from Triple-A Memphis to fill his spot on the 25-man roster. Stavinoha is in uniform and available for St. Louis' Wednesday night game against the Pirates.
"I think we thought maybe there was a possibility of it being a cramp-type issue as opposed to a strain," Ludwick said. "The most disappointing thing is I had this string of a long period of time without being on the DL. ... But the positive is that compared to the other stuff I've been on the DL for, this is extremely minor."
Ludwick was pulled out of Tuesday's game in the bottom of the second after trying to chase down a deep fly ball to right-center field off the bat of Nyjer Morgan -- who ended up with a triple. After Ludwick came up short trying to snag it, La Russa and head athletic trainer Barry Weinberg went out to check on the 2008 All-Star. After walking around a bit, Ludwick was taken out.
The Cardinals currently also have center fielder Rick Ankiel on the DL, retroactive to May 5. They're playing with only 12 position players to go with 13 pitchers, so nearly any injury requires a roster move, or else the club faces a nearly unworkably short bench. Moreover, there was little thought that Ludwick might be ready within a few days.
"There's not that kind of hope," La Russa said. "That's not how we looked at it. We think it's going to take him a couple weeks. Ten days, two weeks."
Stavinoha, 27, was batting .264 with a team-high four home runs and 25 RBIs in 30 games for the Redbirds. He had gotten hot lately, going 13-for-38 over his past nine games after beginning the season in a bit of a funk.
"I was starting to get into a little better rhythm," he said. "I had a little bit of a slow start and was trying to get going."
An outfielder for nearly all of his professional career before 2009, Stavinoha played almost exclusively at first base for Memphis this year, plus one game at catcher. He has not played an inning in the outfield in '09.
"They needed me to play there, and I just wanted to help," he said. "I'll go play wherever they want me to play. I don't care where it is. I just like to be in the lineup. If that's our best chance to win the game, that's where it is. I do the job they ask me to do."
He most likely will be used primarily as a pinch-hitter in St. Louis, though he could start occasionally.
Matthew Leach is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.