Yep. Bruce Kulick, John Corabi, Chuck Garric and, on this tour, Fred Coury.
These days it's basically the same band as Eric Singer Project. Singer has even sat in on drums for Union before.
Originally Union's line-up had Brent Fitz and Jamie Hunting.
23/4 Scott Stapp
25/4 Spirit Caravan
30/4 Kenny Wayne Shepherd