DAVIE - It has been nearly 10 months, and still Ronnie Brown has these moments. The Dolphins running back will move on his surgically repaired right knee — once again powerful, but still fragile — and the pain from last October runs into his mind. Battling back from a torn ACL, even a slight cut brings sharp memories. "It just comes in, on certain cuts it comes in," Brown said. http://www.sun-sentinel.com/sports/football/pro/dolphins/sfl-flspronnie04sbaug04,0,5680165.story
This is the case for most players coming back from a severe knee injury, I know Carson Palmer had a very difficult time coming back from his surgery and the mental aspect played a huge part in that.