So let me get this straight.

You want to move a young 1C who is on a contract that will continue to look more and more like a steal, who is having a career year, when you don't have another young one waiting, because he had a 4 game point drought?

It's not just a 4 game point drought. If you were to actually watch all the games since the all-star break, the guy has been invisible. The non emotion that this guy plays with is bringing down the line. I think he is a valuable piece when he's on his game, but he's too inconsistent.

They would move everyone before Monahan if they want to shake things up. This will never happen. He is on a killer contract.

If this was ever an option to trade SM23 how would this look (or at least start here)

Monahan + Hamonic
for
W. Nylander + Kadri

$$ and term, and ages are close;
CGY gets a skilled W/C and a shut down 2/3 C, and unclogs the RHD
Leafs trim a few $, get RHD, and replacement #3c (or #2, if they want AM34 to take a couple extra shifts at LW)

So count the number of really good centers in the league. Even considering moving a 24 year old that is close to the top 10 scoring centers in the league (11th right now) with a steal of a deal contract for 4 more years is silly but to answer your question it would take a lot. It would be a huge one sided deal that probably not many teams would be willing to make.

Would you take Drouin?

MTL : Drouin

FOR

CAL : Monahan