You don't go from Zero to 60 in 1 step.
Step 1). Meet with agent and inform him that a future contract not a high priority and in fact no contract talks take place other than that.. Marner's agent now gets the message and responds publicly with they have no interest in talking contract either any time soon. So now both sides know where the other stands.
- You need to allow time for the Marner camp come to grips with the situation and then accept the team would like to move on from him.
Step 2) Inform the NHL GMs that you're looking for change, and noting that "you're not going to make change for the sake of change, and Marner is a good player and not going to give him away". So in GM speak this is Marner is available but because he has a NMC there is no use bringing me low ball offers... BT is only going to take serious deals to Marner and his agent to see if they will waive?
- All interested teams are not going to make big offers without getting Marner extended on acceptable terms to team and player where all 3 sides now are happy with return and contract terms .
Step 3) Talk to Darren Farris again with the offer and that this new team really wants Mitch and is looking at a sign and trade deal that woud benefit them and Marner with an additional 8th year term deal, and even allow Farris permission to discuss new contract terms with interested team. If successful the waiving of the NMC to allow the trade to complete is just a formality at that point.
We're only at the very early stages here and have to watch as this unfolds slowly over the summer.. When the shock is over that Marner is accepting his Leafs career is likely over, and unless there is no other options available and Marner then begins to play out the year and BT has not burned any bridges where all options remain on the table. No need to play hardball out of the gate when you can get the end result you still want with patience and willingness to have all side come together.
PS. Treliving did a sign and trade deal with Tkachuk to Florida so has experience on completing one.
a more realistic Step 1) is 2 part
Part 1: Treliving meets with the agent, and finds out what type of salary and term Marner is looking for?
Part 2: then ask him, if a deal presents itself, what would be the conditions that Marner would consider it?
part 1 will obviously get an answer, though perhaps not a realistic one (i.e. 13.5x8 as a starting point)
but, its how the agent reacts to part 2 that will determine if Marner is open to a move or not.
If Marner is not open to a move, you work on part 1, because he is too good a talent to toss away, unless he is actually a 'cancer' in the locker room, but, from everything I heard, he's one of the most popular and liked players on the team, and is involved and friendly with everyone, but, if he has soured, then you tell him that he is no longer in the Leafs plans, and see if he'll move now, or at the deadline.
in your scenario, you burn your bridges with the player/agent before you have any idea of what you can get for Marner, and once you do that, the agent will 'leak' it around the league, and your step 2 will be nothing but lowball offers.
Treliving needs there to be no idea that he is not willing or wanting to resign Marner, and have GM's approach him, wherein Tre can ask if certain players would be on or off the table well before anyone knows his real intention is to deal him.
i.e. Buffalo calls because they really need to make the playoffs, so, you ask, if Power available (because I cant see Buffalo have Dahlin, Power and Byram ...Power straight up or you negotiate for Byram and Benson and then you would to talk to Ferris)
GM's can make hypotheticals to get a framework in place before they speak to the agent/player, as what happened with Markstrom, and Krug, you just need to hope the player is willing to waive, which Marner may not, but, if you PO the player and agent, you will lose him for nothing, and he still may have a career year, as he still needs a big $$ contract.
personally, I do not think the Leafs have any interest in trading Marner.