What Causes Pain Above The Knee While Bending The Leg?

I have pain above my knee when i rise from a seating position and also when i lower into that position. I also have a painful lump below my knee i have had this problem for nearly a year with seeing a physio throughout. What could it be? By continuing to play football am I making it worse? I have recently had 6 week rest period coming back this weekend and it is back to the same level of pain.