The teen bull rider was reportedly in cardiac arrest after the bull threw him to the arena floor.
Animal rights activists have long condemned the event as “one of the most offensive” in rodeos.
Six people were treated for minor injuries after the incident in Redding, California.
The Arizona Diamondbacks pitcher has been competing in team-roping events under the name Mason Saunders.
Players stand in the rodeo ring trying to grab a $100 bill off a bull.