HOUSTON -- Rockets first-round pick Royce White refused his assignment to Houston's D-League affiliate on Sunday in yet another setback to his return to the court.

White, the 16th overall pick in the June draft, has spent most of the season on Houston's inactive list while he and the team figure out how to handle his anxiety disorder and overall mental health.

White's assignment to the Rio Grande Valley Vipers on Saturday looked to be a positive step in his return. But on Sunday, White released an almost 500-word statement where he said he wouldn't report to the team.

"I have chosen to not play, because the doctors and I believe it to be unsafe for unqualified Rockets front office personnel to make medical decisions, as they are not mental health professionals," he said.

The Rockets chose White in the first round after a season at Iowa State, where he helped the Cyclones to their first NCAA tournament berth in seven years by leading the team in scoring (13.4 points a game), rebounds (9.3), assists (5.0), steals (1.2) and blocks (0.9).

The 6-foot-8 White missed the first week of training camp to work with the Rockets to create an arrangement to deal with his anxiety disorder within the demands of the NBA's travel schedule. He and the team agreed to allow him to travel by bus to some games while he confronted his fear of flying and obsessive-compulsive disorder. He flew to Detroit with the team for the season opener and then traveled by bus to Atlanta and Memphis for games.

But he soon stopped participating in team activities and said on Twitter that dealing with his mental health took precedence over his NBA career. Then came his decision Sunday to refuse his assignment to the D-League. Despite the decision, he said he still hopes to return to basketball in the future.

"I do wish to play, but I only intend to do so with the collaboration and recommendation of trained professionals," he said. "The purpose of a doctor's confirmation is to ensure that health decisions are made in the sole interest of health and not conflicted with business. My only hope is that decision makers involved realize that doctors are the only logical source to decide action."