Help? Left pectoral muscle 3 x's larger than right and in severe pain due to pushup & swimming working out.?

My collegiate distance runner son started pushup program 6 days ago every other day combining w/swimming daily as his 2nd workout in addition to a.m. training of 12-16 miles. He's done this for last 3 or so years but just started up pushup program using these black disks with handles he places on floor. In past he's done all 3 levels but is just starting out after a 3 month break. He over did it. His left pec, tri & bi muscles R in pain. Left pec 3 times larger. Took advil, maged w/biofreeze, iced & swam to loosen. No luck. He tried stretching his pecs and arms on doorway. Both pecs, biceps and triceps are sore but Left side severe with again his left pec 3 x's larger than right. Will Left pec swelling go down? What should he do? What do you think he did? I'm flying back home in 2 days & need to know what to do before I feel I can go. He doesn't want to go to a doctor right now cuz he feels he needs to give it time, ice, and hot showers with advil hoping it'll heal on own. Do you thing by me giving him a deep tissue mage it made things worse and if so, what did I do and now what should he do? I really put a lot of pressure. Thanks for your help. Serious responses please.