Danley was struck in the sixth inning by a foul off the bat of Colorado’s Sam Hilliard.
The 59-year-old Danley immediately fell backward, then slowly rolled onto his side and stayed down for several moments as Giants trainers and the other three umpires rushed in.
Danley was eventually helped to his feet and slowly walked off the field as the crowd at Oracle Park gave him a standing ovation.
Second base umpire Ryan Additon replaced Danley behind the plate.