I like Viz, but would prefer him as a 7th or 8th inning guy. If we had him, Britton and Minter, that would be a pretty strong group to handle innings 7-9.
And to pile on to Cy's multiple additions line of thinking, adding two non-elite guys who have been elite for stretches that could come relatively cheaply would really help - ride the hot ones when they're hot, and don't overuse anyone in a particular role. For argument's sake, maybe you try to add Herrera AND Holland on 1-year/$5 million make-good deals? I know I'll take some ridicule for continually pushing Greg, but he finished out strong once he got to Washington - 21.1 IP, 2 ER, 25/10 K/BB, 1 HR.
Wouldn't necessarily have to be those two in particular with several guys available out there with plenty of back-end experience, but adding two of them would give you 4 guys that have proven capable of handling the job (along with Viz and A. J.) to keep from having to put it all on one guy.
Pretty torn about which way I'd go here since I've always been a big fan of having defined pen roles, but I could probably go either way if AA was able to make a couple of relative bargain signings.