The game showcases 38 of the best high school players in the nation, as selected by a committee of Baseball Factory scouts.
McPhearson, a rising senior at Riverdale Baptist in Upper Marlboro, has committed to play for the University of Miami after high school. He is listed as a 6-foot tall, 170-pound lefthanded centerfielder, and is considered to be possibly the fastest player in the class of 2013.
The game will be played at 1:30 p.m. on Saturday afternoon, and will be aired live nationally on the MLB Network.
McPhearson is the only Maryland representative in the game, which last year yielded seven first-round selections in the MLB Amateur Draft.