The St. Louis Cardinals placed DH/1B Matt Carpenter on the 10-day injured list Monday with a lower back strain.
The move is retroactive to Friday for Carpenter, 38, who is batting .255 with three homers in 42 games this season.
The Cardinals recalled outfielder Jordan Walker from Triple-A Memphis in a corresponding transaction.
Walker, 22, opened the season with St. Louis but struggled, batting .155 with no homers and four RBIs in 20 games before being sent down to Memphis on April 24.
He batted .257 with nine homers and 33 RBIs in 78 games with Memphis.