The Undertaker has been battling knee issues, and had a procedure done recently. He had his knee scoped after the 1/19 Smackdown show in Greenville, and had to take a few shows off between then and the Royal Rumble.
HHH replaced Undertaker on some of the shows, moved from the Raw house shows, which already had John Cena to fulfill the “megastar” quotient.
credit: Wrestling Observer Newsletter
