Free agent Mustafa Shakur also signed. Hawes was chosen 10th overall in last week's draft. The seven-foot Hawes, who is 19, led Washington with 14.9 points per game and shot 53 per cent from the floor, all while dealing with an injured knee and ankle as well as a mid-season illness in his only college season.
He averaged 6.4 rebounds, second on the team.
Shakur, a 6-3, 190-pound guard, averaged 10.1 points and 5.1 assists through 131 games during a four-year college career at Arizona. He scored 11.9 points per game as a senior.