Hi My 17 Year Old Son Plays Defense Tackle In

Hi my 17 year old son plays defense tackle in high school and works out with weights. He developed a pain on his chest muscle close to his armpit he calls his peck. It's been two weeks and he still has a lot of pain and can't play . He says it feels hard in the area that hurts , I felt it and it feels like a hard lump ..is this a normal sports injury ?