Here's the post you can bookmark and laugh (or cry) at in 10 years when Andrew McCutchen continues to produce at a Hall of Fame level through his late thirties and Gregory Polanco turns into the next Jeremy Hermida. As I wrote last night, the Pirates probably shouldn't try to re-sign McCutchen right now, unless they can get him to agree to a deal that he probably shouldn't sign. They already have him under control for the next four seasons, and banking on whatever happens after that is too risky.
The Bucs do have a couple other extension candidates, though:
-P- Gregory Polanco. Polanco and the Bucs had discussions at some point early last year that apparently trickled into June, but nothing got done. The Pirates already control Polanco's rights through 2020, but given how far he is from making significant money, he should still be fairly cheap, and 2021 will only be his age-29 season. Contracts for players with Polanco's minimal amount of service time typically include a team option or two, as well, which should help mitigate the Pirates' risk. Polanco struggled in his first exposure to big-league pitching last season, but is talented enough that he should be able to make adjustments. His ability to control the strike zone also bodes well. Anything can happen, but I would treat last season as little more than a bump in the road, and for the right price, I wouldn't hesitate to sign him to the seven-year deal with three team options the two parties were reportedly discussing earlier this year.
-P- Gerrit Cole. Signing pitchers to long-term deals is tricky, and Cole has been merely good, rather than dominant, in his first two years in the majors. There's also the fact that he's represented by Scott Boras, who generally opposes pre-free agency extensions. Boras' actual level of disdain for those contracts is somewhat overstated, however -- plenty of his clients, including Jered Weaver, Carlos Gonzalez, Carlos Gomez, Carlos Pena, and Elvis Andrus, have signed them. Boras won't get in the way if his client wants to take a deal. Meanwhile, Cole still has a very bright future. He beefed up his strikeout rate last season while maintaining a strong ground ball rate and a fastball velocity over 95 MPH. One problem with negotiating with Boras is that he's generally unwilling to include team options, so finding an appropriate extension for Cole would be difficult. But if the Pirates were to get a slight discount on Cole's arbitration seasons while getting him to sign away an extra year of control, that would probably offset the risk inherent in signing pitchers to long-term deals.
Essentially, if the Pirates are going to sign players to extensions, they should sign young, toolsy ones. This is one reason the Starling Marte contract and the first McCutchen deal were good ideas. McCutchen is certainly still toolsy, but he's not particularly young any longer, especially given that the purpose of any new contract would be to sign him beyond 2018. Polanco and Cole fit the bill much better.