I have recently had and ACL reconstruction after injury playing rugby. Obviously i have been sat down a lot in the last couple of weeks (surgery was on the 11th February). About a week ago i was getting pain on my skin on my buttocks where i was sat down and just tried to avoid sitting on these areas. The pain subsided after a few days but in the last couple of days i have found a lump quite deep in the muscle of my right buttock, it is slightly painful when i sit or when i push hard to feel it. There is no redness on the skin and no swelling, the lump is deep in my buttock. Is this anything to worry about? I am a 21 year old female in good health otherwise.