The actor's health issues have forced him to pull out of a theatre production of The Odd Couple.
The 64 year old is expected to make a full recovery after checking into hospital on Sunday (28Oct12).
The Odd Couple director B.J. Jones tells the Chicago Sun-Times newspaper, "George is family to us and we wish him well for a complete and speedy recovery. He will be missed in the rehearsal room and on stage."
The play is set to open on 9 November (12).