Egerton had been starring in the West End play Cock, a revival of Mike Bartlett's 2009 play at London's Ambassador's Theatre, alongside Jonothan Bailey.
It was during this opening night, that the Rocketman star fainted on stage and had receive medical attention from a doctor. The play was able to continue as understudy Joel-Harper Jackson deputised for Egerton.
The production themselves had stated, "During yesterday evening’s first preview of Mike Bartlett’s play Cock at the Ambassadors Theatre, Taron Egerton fainted towards the end of the performance".
"A doctor who was in the audience attended to Taron immediately after the incident, and whilst he felt fine, it was decided that Taron’s understudy, Joel Harper-Jackson would continue in the role to complete the performance".
Releasing a statement, Taron Egerton assured fans that he is in good health.
"As some of you may have heard, I passed out during the first performance of Cock last night", he said. "I am completely fine. Slightly sore neck and a bruised ego but I’m fine".
"I’ve decided to put a positive spin on it and I would appreciate it if anyone who was in the theatre last night just said that I gave such a committed, electrifying performance that my body couldn’t handle it and checked out".
"That being said, apparently you’re meant to actually do the full show and not just three quarters of it. So I’ll be back with a vengeance tomorrow night".
The actor also singled Joel Harper Jackson out for special praise after he replaced him for the rest of the show, adding "Thank you Joel".
Showing his support for Egerton, Joel-Harper Jackson said the performance a "privilege", but insisted that the Egerton's well being was more important.
