Slayer have announced that Exodus guitarist Gary Holt will join the band to fill in for Jeff Hanneman who is currently in hospital being treated for a rare flesh-eating disease.As previously reported, Hanneman ihas contracted necrotising fasciitis on his right arm which doctors believe was due to a spider bite. He is set to undergo surgery next week."We can't pinpoint what day he'll be back, but it will be as soon as he possibly can," said guitarist Kerry King in an official statement. "We can't wait for him to get better and get his ass back on the road."