The miniature T. rex couldn't use its tiny arms to get the ball to home plate, so it opted to chuck the baseball with its teeth.
The home team might have wanted to put the dinosaur on the mound as they wound up losing to Kansas City 8-0.
According to a press release about the prehistoric pitcher:
"The Baby Tyrannosaurus Rex will throw out the Ceremonial First Pitch. Baby T is in San Diego promoting Walking With Dinosaurs, which will be in San Diego November 26-30 for eight shows at the Valley View Casino Center."
Based on the BBC documentary television series and later feature film, the Walking With Dinosaurs "arena spectacular" is a live-action performance.
Kansas City took the three-game series at Petco Park two games to one.