On their Web site Wednesday, the Cardinals said they have recalled outfielder Nick Stavinoha from Triple-A Memphis to fill Ludwick's spot on their 25-man roster.
Ludwick was hurt in the second inning of Tuesday's 7-1 loss to the Pirates while trying to run down a triple by Pittsburgh's Nyjer Morgan and was replaced by Colby Rasmus.
He is second on the team in homers (8) and RBI (26) and has .274 batting average.
"(Initially) I knew it wasn't anything super-serious," Ludwick said Tuesday. "I didn't feel a pop (but) when I came in, that's what I said, it could be worse.
It's just one of those things where I've got to get back healthy, get it strong again and get ready to play."
Stavinoha was batting .264 with a team-high four home runs, 25 RBI and .427 slugging percentage in 30 games at Memphis.
Copyright 2009 by United Press International.