The actual diagnosis is somehow worse.
The Oregonian's Jason Quick reports that Roy will avoid surgery, but has been diagnosed with "arthritic knee," which will require the guard to take anti-inflammatory medicine daily, will cause pain so long as Roy runs and jumps using his left leg, and means, effectively, that the Roy who swept into the NBA into 2006 is no longer the Roy under Blazer employ. The less-explosive Roy seen this season is the new Roy, and from Quick's telling there appears to be little chance the old one will ever be able to return.
The specific problem is the lack of cartilage in Roy's knee, which causes bone-on-bone friction. That leads to swelling, and that makes the knee less mobile. The medication Roy has begun taking to decrease the swelling and allow more free movement in the joint causes liver problems, Quick reports the Blazers will continuously monitor Roy's liver to ensure permanent damage is not being made.
The other prescription is likely even more painful for Roy: the doctors want him to play less (he's capped at 35 minutes a game right now) and practice less. Roy is by far Portland's best player, and has averaged 37 minutes a game over his career.
Roy's five-year, $82 million contract just took effect this season. FanHouse's Chris Tomasson talked to Roy about his knee and the extension (which is not fully guaranteed) in December.