If this situation is true, the Canucks might be best to trade both of them for great packages, similar to when the Flyers traded both Richards and Carter within hours on the same day. Trading one of them could be a no-win situation...
Scenario 1: Trade Miller & keep Pettersson
This is the most likely option, considering Pettersson is younger, more skilled, and a fan favorite. But this has the potential to backfire since Miller is the type of player who could explode on his new team and put up gaudy numbers in bunches. If that were to happen, the pressure on Pettersson to reemerge as an elite producer would increase 10-fold which could amplify the fan's frustration if he falls short. And the ensuing drama could be disastrous.
Scenario 2: Trade Pettersson & keep Miller
If this were to happen, most of the hockey world (mainly Canucks fans) would believe the club "chose Miller over Petey" and that could lead to verbal pitchforks being used against JT. If Pettersson were to thrive in his new surroundings, and/or Miller struggled in Vancouver, the fans could turn on the player, management, and even Tocchet... and towards the most crucial time of the year. If the Canucks felt forced to deal Miller at the deadline, the narrative would be that they traded the wrong player off the rip and the organization needs to be held accountable. Again, disaster.
Scenario 3: Trade both players at the same time
While very unlikely, IMHO, this could be the best decision for the Canucks in terms of risk/reward and potential fall-out. Best case: the players rally around the move and the incoming bodies help team chemistry and the Canucks move on. Worst case: One or both players get a new lease on life in a fresh market and play great hockey. While that would sting, the reality is that there is currently an issue that needs resolving and Pettersson hasn't been the same player since he inked that massive deal. Fans have seen enough to know that "change" was likely inevitable. Using the Richards & Carter example... both of those players went on to greener pastures and won Cups... but Flyers fans took it in stride because:
A.) They realized that both moves needed to be made for multiple reasons
B.) The team acquired significant pieces in return (ended up being Simmonds, Schenn, Voracek, and the pick to land Couturier).
Trading both players deflects the blame toward them (i.e., they couldn't coexist in Vancouver which is their fault and not the team's). In this day and age, I feel that the average fan can't relate to multi-millionaire, professional athletes underperforming because they cannot overcome a squabble.
Scenario 4: Keep both players
Status quo. Smoke, rumors, drama.