Mr Rosell qualified in 1991 from Guys Hospital, London. Whilst at University, he joined the Army as a medical officer, which is a post he continues to hold.
After Mr Rosell qualified, he worked at The Cambridge Military Hospital, and acted as the Regimental Medical Officer to the 1st Bn Parachute Regiment in Aldershot.
Mr Rosell carried out his surgical training at Portsmouth and Frimley hospitals, with a plastic surgery post in Salisbury. Following this, he completed his orthopaedic training in Wessex. Mr Rosell held a sports trauma fellowship in Grenoble, in the French Alps, during 2004 and 2005, where he was involved in developing computer aided surgical techniques.
Prior to commencing his consultant post at Frimley Park Hospital, Mr Rosell was offered a shoulder surgery fellowship in Oxford, under Professor Andrew Carr.
Mr Rosell remains as a regular officer in the Royal Army Medical Corps and was deployed to the Middle East during the 2003 conflict, working at the main UK field hospital.