The pitcher would either need to be very good (think Ace-level) for 4-5 years, or just good enough, and young enough, to hold down a rotation spot for a decade. Outside of the obvious guys like Peralta and Burnes, who are young and have ace-level stuff, the guy that comes to mind is Zach Davies. He's only 26, and is already off to a nice start win total-wise. He's not a power pitcher, and is just good enough to hold down a mid-rotation spot for the next decade. Yep, Davies is the one I was thinking of as well. He could plausibly be halfway there at the end of this year and would still only be 26. He's the kind of candidate you're speaking of I think -- back end of the rotation guy who is good enough to probably hold a spot down for 10 years. The only issue is, back end of the rotation guys aren't very hard to replace, so I doubt the Brewers would pay enough to keep him if he hits free agency. It would have to be a kind of contract where Davies gives us a team friendly long term deal early on, like right now. Furthermore he's a Scott Boras client who doesn't sign many of those types of deals.