“Meanwhile, anyone who had tickets for tonight’s show will be contacted about the next steps, with the performance cancelled to give the stage and screen icon time to recover.”
The statement continued: “The production has made the decision to cancel the performance on Tuesday, June 18 so Ian can rest.
“Those affected will be contacted by their point of purchase as soon as possible tomorrow.
“Thank you to doctors Rachel and Lee who were on hand in the audience and to all the venue staff for their support.”
McKellen - who plays John Falstaff in the production - was amid a fight scene when the incident occurred.
The veteran actor cried out in pain after he fell off the stage and theatre staff rushed to help him.
One audience member told the BBC that the incident was “very shocking”.
Sandro Trapani added: “I really hope that he is going to be alright. As far as I saw, he was conscious because he was asking for assistance.”
Player Kings began its 12-week West End run in April, and McKellen previously admitted that he was relishing the opportunity.
He told the BBC earlier this year: “Actors who have taken on the role say it is verbally very challenging - it seems that the role was written for a particular actor and comedian in Shakespeare’s time, so it’s a bit like being given a script for Michael McIntyre.”
