My Hard Working 16 Year Old Son (VFD, School-graduating HS

My hard working 16 year old son (VFD, school-graduating HS a year early, regular job and odd jobs) bumped into a counter at work last Sunday on his backside. It progressively got worse during week(affecting his sitting and walking) and he woke today with bleeding as it had developed into a large hematoma and abscessed. After trip to ER at Children's hospital (very good experience) I am left with some concerns after thinking over tests and doctor concerns. Abscess drained and left open as due to large size- antibiotics prescribed- fever present. More concerning was the lab results(and the doctor's concern for them) about his high bilirubin(spilling into urine) and low platelet count. His hemoglobin levels were good. Was diagnosed with large spleen/mono a year or two ago. Son does not currently have a PCP and I am concerned about taking him to someone new vs my doctor who is over an hour away from home and different hospital system, but is someone I extremely trust. Guidance appreciated.