-- Chris Jericho will definitely not be at the Royal Rumble this year as he is touring with his band Fozzy from January 28 to February 13 and the PPV is taking place on the 28th. As for if or rather when he will return, there has been talk that it could be at the Raw 25th Anniversary show in January but ultimately it depends on his touring schedule, with February 13 being the last publicized date.
-- Scott Dawson of The Revival is scheduled to be returning around the middle of December. He has been sidelined since August after undergoing surgery for a torn bicep.
Source: Wrestling Observer Newsletter. Subscription information & prices available at f4wonline.com
