Two of the biggest boppers in baseball history are set to be two of the next signers in the PSA Autograph Series. Want your cards, magazines, and jumbo items signed by Mark McGwire, Sammy Sosa, or both sluggers? Make sure your items arrive at PSA by August 27.

Two of the biggest boppers in baseball history are set to be two of the next signers in the PSA Autograph Series.

Want your cards, magazines, and jumbo items signed by Mark McGwire, Sammy Sosa, or both sluggers? Make sure your items arrive at PSA by August 27.  psacard.click/Auto-HR-x

— @PSAcard Jul 23, 2026