Many players get injured and fewer are hit with an injury bug that forces them to warm the bench for much of their careers.

However, it's downright rare for an injury to abruptly cripple a player's career, forcing them into retirement.

That's the case with Portland Trail Blazers guard Brandon Roy, who, according to ESPN, will be announcing his retirement due to degenerative knees, something that has plagued Roy since his college days at Washington and something that has reduced his role on the team in recent years.

Portland

Portland Trail Blazers guard Brandon Roy, according to ESPN, will be announcing his retirement due to degenerative knees, something that has plagued Roy since his college days at Washington and something that has reduced his role on the team in recent years. (Reuters/Steve Dipaola)

According to reports, the Blazers had said earlier in the week they were expecting Roy to be ready for training camp Friday after a grueling five-month lockout. However, the bug had probably been troubling Roy so much that he made a decision to walk away, knowing that if he were to continue fighting, he would most likely still maintain a reduced role, maybe even relatively no role at all.

The downward spiral really began during the 2008 preseason when Roy had a piece of cartilage in his left knee removed. Ironically, though, Roy still had his best season with the Blazers that same year, being able to start the season and eventually averaging 22.6 points per game. Many started to consider him a legitimate, big-game player after that, especially because of his emergent clutch performances during the season. Roy hit a game-winning, 30-foot buzzer-beating jumper in overtime against the Rockets in November. In February, Roy made a buzzer-beating layup at the end of regulation against the Knicks.

However, in April 2010, Roy tore the meniscus in his right knee. He returned to play sooner than expected in the playoffs, and had enough juice to propel the Blazers to a Game 4 win in the first round over the Phoenix Suns. Roy also had a standout playoff game in 2011 playoffs' first round against the Dallas Mavericks, in which he scored 16 points in 23 minutes. Nevertheless, the combination of the meniscus tear, the lack of cartilage following the 2008 operation, and the ever-bothersome resulted in Roy being sidelined indefinitely last year.

Now, the Blazers run their offense through breakout star forward LaMarcus Aldridge and rely more heavily on guard Wesley Matthews. Yet, without Roy, the Blazers have lost their big-play ability.

When word came of an amnesty clause in the newest collective bargaining agreement, which allows teams to cut one highly-paid player in order to save salary cap space, many expected Roy to get the axe as recently as Monday. However, Blazers officials had said that they wouldn't use the amnesty clause on the two-guard.

Amnesty clause or not, Roy's retirement would eventually give the Blazers salary-cap relief. According to ESPN.com, league rules call for a waiting period of one year from the date of the player's injury, after which the Blazers could get Roy's contract completely off their books. Because Roy played all the way into the playoffs last season, that date will likely be April 28, 2012-one year from the day the Mavs eliminated the Blazers from the playoffs.

According to NBA rules, a league physician will have to confirm first that Roy is unfit to play for the Blazers to get the salary-cap relief.

With Roy gone, Matthews is more than capable of being the starter at shooting guard for the Blazers come their season opener versus the Philadelphia 76ers. At the same time, if the Blazers want to regain a big-play player, they can set their sights on the Atlanta Hawks unrestricted free agent guard Jamal Crawford, who also has had buzzer-beaters of his own.