Greer attended Temple University, where he played college basketball for John Chaney's Owls.

He led the Owls to the Elite Eight in 2001, where they lost a tightly contested game to #1 seed Michigan State.

In July 2006, he was signed to a multi-year contract by the NBA's Milwaukee Bucks, a team he played with in the pre-season of 2003.

His final NBA game was played on April 18, 2007, in a 96 - 109 loss to the Cleveland Cavaliers where he recorded 5 points, 2 assists and 1 rebound.

Greer grew up in Southwest Philadelphia, and played against many NBA players, including Kobe Bryant, Jameer Nelson, Ronald "Flip" Murray, Rasheed Wallace, Richard "Rip" Hamilton, Malik Rose, Malik Allen, and Cuttino Mobley.