The Chicago White Sox placed pitcher Philip Humber on the 15-day disabled list with a right elbow flexor strain on Friday and purchased the contract of pitcher Brian Bruney from Triple-A Charlotte.
Humber, 29, tossed the 21st perfect game in Major League history during a 4-0 victory over the Seattle Mariners on April 21, but has managed just two wins over 10 starts since then and owns a 3-4 record with a 6.01 earned run average overall this season.
The move is retroactive to June 17, one day after the right-hander tossed five innings and allowed four runs on nine hits in a 5-4 victory over the Los Angeles Dodgers.
Bruney went 1-3 with a 1.85 ERA and 11 saves in 23 games -- three starts -- with Charlotte this season.
Chicago also designated outfielder Kosuke Fukudome for assignment on Friday after reinstating him from the 15-day DL.
The 35-year-old outfielder hit just .171 with four RBI in 24 games for the White Sox this year before suffering a strained right oblique.