The Chicago Cubs placed right-handed pitcher Jameson Taillon on the 15-day injured list Thursday with a left groin strain.
Taillon was scheduled to start Thursday night's game against the visiting Los Angeles Dodgers. The Cubs recalled right-hander Javier Assad from Triple-A Iowa to start in Taillon's place.
Cubs manager David Ross said Taillon got hurt while playing catch on Wednesday on flat ground in Oakland.
"Just felt a little something in the groin and didn't feel like that's something we should push," Ross said. "It's pretty sore. Got some work on [it], loosened up a little bit, but then some time went by, tightened back up. Hopefully it's [a] minimal stay on the IL."
Taillon, 31, is 0-2 with a 4.50 ERA over the first three starts of his first season in Chicago. He signed a four-year, $68 million contract in free agency, coming over after two seasons with the New York Yankees.
Assad, 25, has a career 2-3 record and 4.07 ERA in 11 games (eight starts) for the Cubs since making his MLB debut last season. Assad has made one start at Iowa this season, along with two relief appearances for the Cubs.
Reuters and The Associated Press contributed to this report.