“While you are protected by the Hammer abilities “Enter the Fray,” “Thick Skin,” “Raging Volcano,” “Juggernaut,” or “Die Hard” your Hammer abilities deal 8.5% more damage and attacks against you generate 2 more Rage.”
At the moment Enter the Fray needs the Brawler passive to trig this effect, and Thick Skin doesn’t exist anymore. (Thick Skin replacement Blazing Fury also doesn’t trig it.)
Raging Volcano, Juggernaut and Die Hard seem to work ok.