Chad Ford is reporting that the Celtics have promised to pick Royce White if he's available at pick 21.

Looks like a team may have promised Royce White. He's pulled out of all remaining workouts and gone silent. Not injured.

— Chad Ford (@chadfordinsider) June 22, 2012

More on Royce White. Now hearing more definitely promise is from Celtics at 21.

— Chad Ford (@chadfordinsider) June 22, 2012

More details on Royce White:

Green Street » NBA Draft’s Potential Celtics: Iowa State PF Royce White

White is a unique talent in this year’s draft. At 6-foot-8 and 260 pounds with a 7-foot-1 wingspan, his size and strength make him an excellent rebounder. But White also maintains the quickness and ball-handling ability of a much smaller player, making him a matchup nightmare for many power forwards. Perhaps White’s most impressive skills however, are his court vision and passing ability. Asked to dominate the ball as a point forward at Iowa State, White was able to showcase his tremendous versatility, becoming the only Division 1 player to lead his team in points, rebounds, assists, blocks and steals.

Like other players slotted to be available when the C's pick him, he's got his own "red flag" issues, including an anxiety disorder (related to flying) and a few run ins with the law. Though it has been reported that he's been very up front and open about his past which impressed GMs.