PORTLAND - NBA training camps had barely opened when the Portland Trail Blazers were blindsided by bad news about a trio of stars: Brandon Roy, Greg Oden and LaMarcus Aldridge.

Hopes that the three could form the core of an NBA championship team were dashed as Roy opted to seek a medical retirement because of the continuing knee problems that sidelined him for much of last season.

"My family and health are most important to me and in the end this decision was about them and my quality of life," Roy, the 2007 NBA Rookie of the Year, said in a statement issued by the team on Saturday, a day after reports of his decision broke.

Meanwhile Oden suffered another setback with his surgically repaired knee, and Aldridge was found to require treatment for a pre-existing heart condition when he went for an exam on Friday.

Roy's premature departure from the league was the most stunning news.

On Saturday the three-time All-Star confirmed he would seek medical confirmation that he had suffered a career-ending injury to his knees.

Portland could still use the league's new amnesty clause to waive Roy, so that his guaranteed salary wouldn't count against the salary cap, but acting general manager Chad Buchanan said Friday night they hadn't decided if they would.

Team owner and Microsoft co-founder Paul Allen issued his own statement on Saturday thanking Roy for his five seasons with the Blazers.

"Like every Blazer fan, I am very sad to learn that Brandon's playing days have ended," Allen said.

"Up until Thursday night we were looking forward to seeing him back on the court Friday for the first day of practice."

Miami's Dwayne Wade praised Roy via Twitter.

"I want 2 show my respect 2 1 of the best 2 guards 2day," Wade said on the social networking site. "The game will miss Brandon Roy as much as he will miss the game."

Oden's news was also an unwelcome surprise. The seven-foot center had appeared to be making good progress after microfracture surgery on his left knee and in line to resume playing in late January after almost two years sidelined by various injuries.

As a restricted free agent he had agreed to accept Portland's $8.9 million qualifying offer for another season with the team that made him the top overall pick in the 2007 draft and supported him through a spate of injuries.

Buchanan, however, said an MRI of Oden's surgically repaired knee had revealed a setback.

"We're hopeful that Greg can get back out on the court this year - maybe not quite as optimistic as we were before - but we feel like Greg Oden is worth that risk for one more year," Buchanan said.

The news on Aldridge appeared less far-reaching, but unsettling as his cardiologist recommended he have a procedure to treat Wolff-Parkinson-White Syndrome, a condition which causes the ventricles of the heart to contract prematurely.

Aldridge was diagnosed with the condition in 2007 and missed nine games after a similar procedure.

The team expect him to miss less than two weeks and be ready for their opening game of the lockout-shortened season on December 26.

"Thanks for the support everybody," Aldridge posted on his Twitter account. "I'm feeling better and will be ready to go in a few days."