The 23-year-old actor, who was spotted leaving the Noel Coward Theatre on July 18, was looking tired, pale and skinny and has sparked fears for his health, reported Us magazine.
His representative has revealed that his appearance is all down due to his role in the Martin McDonagh play 'The Cripple of Inishmaan', which is currently playing at the Noel Coward theatre.
"It is a very demanding role, physically. At every night's performance, there is a large crowd at the stage door and he takes the time to sign autographs and pose for pictures at length," the representative added.