The team recalled catcher Joey Bart and outfielder Luis Matos from Triple-A Sacramento and optioned outfielder Wade Meckler to Sacramento in corresponding moves.
Bailey, 24, was removed in the ninth inning of Tuesday's 11-8 loss at Chicago. He was involved in contact at the plate with the Cubs' Jeimer Candelario in the seventh inning.
"I think he took a shoulder to the chin, and he was a little lightheaded," Giants manager Gabe Kapler said after the game. "We had to get him out of there."
Bailey is batting .248 with seven homers and 45 RBIs in 84 games since making his major league debut on May 19.
Bart, 26, is slashing .231/.286/.295 with zero homers and four RBIs in 26 games with the Giants this season.
Matos, 21, made his MLB debut on June 14 and batted .250 with two homers and 11 RBIs in 59 games.
Meckler, 23, debuted on Aug. 14 and batted .232 with four RBIs and 25 strikeouts in 20 games.