Brandon Roy, the NBA's rookie-of-the year in 2007, has decided to retire after just five seasons because of serious knee problems, The Oregonian newspaper reported. The 27-year-old shooting guard, who did not report for Portland's first day of training camp on Friday, has undergone a half-dozen knee surgeries in his career, including last January on both his knees. Roy discussed his degenerative knees with team doctors Thursday after which the decision was made, according to a report in The Oregonian. He has been dogged by problems since his US college days and lacks cartilage between the bones on both knees. Doctors apparently told Roy he risks not being able to walk if he continues to play. Roy's teammates reacted to the news with surprise and sadness on Friday as they assembled for their first practice since the NBA lockout officially ended. "I couldn't believe it," Blazers forward Nicolas Batum said. "I still can't believe it." Said center Marcus Camby "It's a tough situation. People will say 'Hey, he'll get his money.' But Brandon's a competitor." Roy averaged 19 points, 4.7 assists and 4.3 rebounds over his career but did not play for long periods last year, coming off the bench when the Blazers needed his scoring. Former Blazer Martell Webster, now with Minnesota, wrote on his social networking Twitter site: "B Roy the league just lost a legend. I Was looking forward to watching for another 10 years. You will be missed, I'm calling a comeback 2014." Roy's agent could not be reached for comment Friday. NBA spokesman Tim Frank said the league have nothing official on Roy's status as he has not yet filed any retirement papers. If Roy does files for medical retirement his salary would not count against Portland's salary cap after one year.