Back of Ankle

Firstly, apologies for the un-technical title. I dont know the medical term for the area.
While playing football a few weeks ago I was tackled and the player landed on the back of my ankle. initially it hurt but after a few minutes the pain subsided.
I have played twice since and while warming up I felt pain in this area when pointing my foot upwards. Afterwards it has been sore.
Can anyone tell me what I may have done and if there is anything I can do cure it besides rest

Thanks for any advice