You can refer to an actor or other performer as a trouper, especially when you want to suggest that they have a lot of experience and can deal with difficult situations in a professional way. Like the old trouper he is, he timed his entry to perfection
(deyim) A real trouper is someone who will fight for what they believe in and doesn't give up easily. (People often use 'Real trooper' as the two words sound the same.)