Suggest Remedy For Rash Above Right Ankle

I am a 21 year old male. 5, 10 and weigh 160 pounds. i have over the pst few month noticed a red rask just above my right ankle, it does not itch but there is a bump underneath. This is in fact an area where i had a bad tackle on me at football but that was 18months ago. Also, i have started going to the gym regularly and my calf muscles seem more defined. could this be the cause of the bump revealing itself