Although Penn was selected in the 2000 NBA Draft by the Atlanta Hawks with the 57th overall pick, he never played a single game in the league.

He made his big splash with the Adriatic League club Crvena zvezda (Red Star Belgrade).

At the beginning of the 2009–10 season, Penn made the move to the Italian League, to play with Virtus Bologna.

On New Years Day, 2010, it was announced by Greek powerhouse Olympiacos, that Penn would return to the club, to replace Von Wafer, who had been released, due to his inability to adapt to the European game.

[1] As a member of Team USA, Penn won a gold medal at the 1999 Palma Summer Universiade.