Dumas averaged 18 points over 18 games for the Phoenix Suns, including a 32-point haul against the Chicago Bulls in 1992, before his career was interrupted.
He avoided prison last month when he pleaded guilty to a charge of cocaine possession, and a misdemeanour of possessing drug paraphernalia, in his home state of Oklahoma.
Storm's owner Mike Horton said: "Richard will spend some of his time giving talks about his experiences. He will point out to young people how poor decisions led him to waste some of the best years of his life, telling them never to go down the same road.
"No one is sweeping Richard's past under the carpet, but we believe far from setting a bad example he will prove to be a good example to youngsters."
The International Federation (FIBA) gave Dumas clearance to play last season in Poland and he received a work permit this week.Reuse content