Michael Lorenzen smashed MLB's baseballs after striking Justin Upton in the head.
Upton was making his season debut when he was hit in the helmet by a 90.6 mph fastball from Lorenzen. He lay on the ground for a while before leaving the field.
Seattle manager Scott Servais said Upton was alert and chatting throughout the game.
Lorenzen blamed the incident with Upton on "slick" baseballs.
Lorenzen added, quoting Ben Verlander of Fox Sports, "I don't know what Major League Baseball is playing with these baseballs."
"That's insane. As a child, you think MLB is the best thing ever, but now you're like, "What are they doing?" Baseballs are suddenly changing...