Kadri is probably worth a late first and a b-prospect at best. Maybe the Leafs could ship him off for a #2/3 defenseman of equal value. I've seen some Leafs fans suggest he is worth a top ten pick, but I just don't see it.
He's had good possession numbers for the last year or two, but his offensive numbers have taken a major dive. He's gets a lot of excuses (bad teammates, unlucky shooting percentage, not enough playing time), but to me a see a player who doesn't utilise his teammates and takes a lot of weak wristers from bad angles.
He does have a nasty edge to his game. Sometimes he can cross the line and throw some boderline dirty checks. He's also gotten a reputation as a diver.
I think he's a decent 2nd liner on an okay team, and a good third liner on a great team. Whether he's worth the money or the cost he'll likely get (late first/b-prospect) is up to the team who wants him.
To be honest, I think the Leafs are better off keeping him for now. Maybe he was worth trading before the extension, but that's a big contract to move and our center depth isn't so great until Matthews (and maybe Nylander) step up.
I've also been called a Kadri hater for suggesting that he was barely a 50-point player, so who knows. It seems like every season he's perpetually ready to break out but JVR or Komarov or Bozak or player X is holding him back from greatness.