knee trouble

[Adam14]

Hey i play 5 a side footy twice a week, recently after a game i have been getting pain in the back of my left knee. its not an impact injury from a challenge and its not a knee twist injury which i have had before, i'm 25 and am stuffed as to what the problem could be. Can any one help,its only really painful when i try to stretch my knee out, doesn't even hurt when i'm running on it? wierd!

[alijangra]

hamstring problem maybe? Try some warm up stretches before you play.