if they stay hot, the devils aren't trading all of that for a ufa carlsson. so carlsson negotiates a contract with devils when he's a capital?

I think you just would make the picks conditional. Look what caps have up for shattenkirk last year.

The lightning did the same thing with Shattenkirk last year. They had a deal in place with Tampa, but only would do it if shattenkirk agreed to 7 year deal. He didn’t want to so Deal didn’t go through.

one difference is that Tampa thought they were out of the playoff run. certainly the caps will be in the playoff hunt. certainly Carlson would get offers better than 5 X 6m that you suggested.

I think there's some confusion for pending UFAs and negotiating contracts between teams because I've seen people post

I think there's some confusion for teams wanting to trade for a player on an expiring UFA contract because many people have asked this question. A team may ask permission to talk to the player and agent about contract status before he's traded. They obviously can't agree to anything so it's a taking your word for it agreement, but two sides can work out the details. That's what the Sens and Canucks did with Burrows. Burrows only agreed to be traded if he was offered a contract. The Sens worked out an extension and then Burrows signed the 2 year extension shortly after being traded.