The user account belonging to Joey Casselberry had been deactivated as of Saturday night, but screen captures of the tweet show that the player used an offensive word while criticizing news that a Disney Channel movie was being made about Davis.
Casselberry made reference to Davis' loss to Nevada during the LLWS.
Bloomsburg announced the dismissal of the junior first baseman on Twitter. The university in Pennsylvania said it was "deeply saddened" by the player's tweet.
Davis, from Philadelphia, was the first girl to earn a win and pitch a shutout in the LLWS last summer, and appeared on the cover of Sports Illustrated.