Z is still good enough to put a good team over the top as far as cup contention. If someone wants him they should have to pony up a very hefty ransom, because for this year's playoffs the guy is still a very formidable player and as a 2nd or even 3rd line center on a contending team he will contribute a boat load. His numbers this year are very good and that is no illusion, he's been our best player by a wide margin. He's slowed down but his play making and drive seem to be what they've always been, and the guy can protect the puck like nobody's business.
I would expect a first and one or two very solid, high end prospects because this is a guy that would make a contending team a favorite, he's still that good at this moment in time.
The Wings can't trade him. If they trade him right now... Here's what it could look like in a couple years...
Cap Benefit: $11,983,336.
This number would be locked in for Detroit (as Z would technically be "retiring" from Detroit for the purposes of this calculation)
Retires summer 2017: ~$3M for the next four years.
Retires summer 2018: ~$4M for the next three years
Retires summer 2019: ~$5.95M for the next two years
Retires summer 2020: ~$11M for the 2020-2021 season.
If he's still putting up .60-.80 PPG somewhere, they're not gonna want Z to quit, and they're paying him pennies on the dollar for it. And hell, even if he sucked... they'd be worth keeping him on for at least two years (17-18, 18-19) so they don't get hit by any recapture themselves. So, you're basically guaranteeing that Zetterberg's full cap hit will be on the books until the end of his contract. Good call.