Plate umpire Jerry Layne had to leave the Colorado Rockies' 11-7 win over the Arizona Diamondbacks in the bottom of the sixth inning after a foul tip off the bat of Randal Grichuk struck the upper edge of his face mask.
Layne left the field under his own power, escorted by Rockies medical personnel for further examination and treatment.
The game was delayed for several minutes while Chad Whitson donned protective gear before moving behind the plate.
Layne had initially ruled that Grichuk had been hit by the pitch, but replay review determined that the ball nicked the knob of Grichuk's bat before skipping off catcher Carson Kelly's glove and striking Layne's mask.
The Associated Press contributed to this report.