Dubois wasn't even close to stop Johnson so might be a good comparison. I think Hrgovic has more variety than Dubois and is probably the much better boxer so i can see a mid/late round stoppage and that's my pick.
Johnson is in the journeyman stage of his Career, meaing he wont really try to win just survive. so hrgovic should have no Problem. personally, i think perea would have been the better Opponent cause he would have tried to win.
Hrgovic should have no problems with Johnson, clear UD or late stoppage. Johnson is still durable and cagey, only guy to legit stop him was Joshua, the Milas stoppage was due to a cut so if it goes the distance that isn't a big deal.
Hrgovic by UD, if Sean Turner can take him 8 rounds then I don't see why Johnson won't go the distance. At least Hrgovic will get rounds in.
Johnson is taking this on very short notice and had a fight last weekend in Germany I really can’t see him going the distance.