Doctors having training in physiotherapy(physios) as well as sports medicine should attend to Coltens injury. As certain injuries like this one, are very common among sports professionals, Sports medicine training easily allows the doctors to judge the type of injury undertaken and the method of treatment required.
As Colten needs rehabilitation , a physiotherapist is a must for this purpose as physiotherapy is the best way of rehabilitation amongst athletes.
I would tell them to tell a trusted adult and use a helpline like nsvrc.org as a resource. Be there to support them during the aftermath as it will take a toll on their mental health.