Starting Wednesday, McKean was replaced in the political comedy by James Lecesne in the role of Dick Jensen, Broadway.com said. Fred Parker is taking over Lecesne's usual role of reporter Mitch Graham in the production.
McKean, 64, suffered a broken leg, bruises and lacerations in the incident Tuesday.
"I have worked with Michael on three previous productions -- 'The Homecoming,' 'The Pajama Game' and 'Superior Donuts' -- and he has never missed a performance, and I understand from his team that he has never missed a performance in his career. So this is the kind of first we are reluctant to announce," producer Jeffrey Richards said in a statement. "Jerry Frankel and I look forward to working with Michael again on a future project."
McKean is also known for his work in the films "This Is Spinal Tap," "Best in Show" and "For Your Consideration," as well as TV's "Laverne & Shirley."
He and his wife, actress Annette O'Toole, were nominated for an Original Song Oscar in 2003 for "A Kiss at the End of the Rainbow" from "A Mighty Wind."