Originally Posted by makethemsuffer12
"With Gary Holt still handling guitar duties for Jeff Hanneman on SLAYERís North American and European tour, EXODUS has invited out none other than former band member Rick Hunolt to fill-in for the bandís upcoming shows. "
From Exodus' statement about Gary filling in for Jeff. So I'd say Jeff's sitting out Mayhem as well.
I'm a little shocked that he would agree to fill in for Jeff with his band already scheduled to play.