hi i've just started playing soccer after a few years out, after practise recently my left knee started to feel very bruised and its been hard to stand on that leg, especially after having my knee bent for a certain amount of time. There's no bruising, just a similar pain. After a few days rest it felt fine so i played again, and now its back to the same but its taking longer to heal. The pain is just after where my quadriceps ends and a little on the side of the knee. Any idea what this could be, thanks.