We'll start with the bad news first. You may already know that without successful treatment your risk for knee osteoarthritis later in life goes up by a factor of five. This five-fold increase in risk is probably the result of high joint stress during the game. Soccer players are known for injuries because of frequent pivoting, rapid changes in speed, and collisions with other players.
The good news is that new treatment methods such as cartilage (chondrocyte) transplantation has made if possible for players to get back into the game. Those who return to competitive or high-level sports are able to return to their previous level of skill.
According to researchers the average time off is 18 months so it's not a quick fix. But follow-up as much as nine years later showed that some players were still able to maintain their level of play.