Strained Ligament or Surgery?

A few years ago I hurt my knee while playing soccer. I iced it, took ibuprofen, and just dealt with it. Since then it has progressively gotten worse. Last week it was hurting pretty bad, but once again I iced it, took ibuprofen, and ignored it. I had 6 basketball games this past weekend, and at one of the games I fell on that knee, and then continued to play 4 games after that, which caused a lot of pain. I went to the doctor yesterday who said he thinks I just strained and possibly slightly tore a ligament in my right knee, but it's hard to tell if the pain is coming from the joint and muscle or from the bruise that's there from falling. I have to wear a brace until next week, when I'm scheduled to go back to the doctor. If my knee is still sore, and difficult to walk on then I have to get an MRI, so that they can look at the muscles to make sure I didn't tear anything. However, if I did tear a muscle I'll have to get surgery, and will be out of basketball, volleyball, and soccer for a while. I'm wishing and praying that everything comes back okay, and that I don't have to get surgery.