MONTREAL — Senators star defenseman Erik Karlsson sure seemed chatty with his Lightning friends as he left the Canadian Tire Center on Thursday night.

Karlsson, 27, took his time talking up several members of Tampa Bay's staff in the hallway outside the dressing room. The two-time Norris Trophy winner got to know the Lightning group a lot more during the January All-Star Game in Tampa, staying all weekend at good friend Victor Hedman's Davis Islands home. And it's common for opposing players to visit with each other postgame. It's a small world, after all.

But with Karlsson the biggest prize heading into Monday's 3 p.m. trade deadline and the Lightning likely one of only a few teams that could pull off such a blockbuster, it sure made for some interesting optics.

It is still a long shot for any team to land Karlsson by Monday. But it's not impossible, and that's what will make the next 72 hours so intriguing.

Lightning general manager Steve Yzerman said Thursday he doesn't plan to deal from his current roster, preferring to build around young players such as Brayden Point and Mikhail Sergachev. Yzerman said he doesn't believe in getting a player "at all costs" and will offer only prospects and picks.

That sounds like it would be difficult for the Lightning to satisfy the likely astronomical demands the Senators have for the face of their franchise.

But former NHL GM Craig Button thinks there are ways the Lightning could acquire Karlsson without tapping into its current roster. Tampa Bay has a very deep prospect pool and all its draft picks for the next three seasons, which creates the potential for a strong futures-only package.

Button suggested that Taylor Raddysh, Cal Foote and Boris Katchouk are A-level prospects, with the Lightning also having former first-round pick Brett Howden, Mitchell Stephens, Libor Hajek, Anthony Cirelli and Mathieu Joseph.

For example, Button said, the Lightning could pitch Raddysh, Katchouk and Foote with a draft pick and go from there. And if you're Senators GM Pierre Dorion, you'd have to think about a deal like that. These prospects are players that Senators fans have likely seen star for Canada at the World Junior Championships and likely will be in the junior Canadian Hockey League's Memorial Cup tournament in the spring.

"If I'm Pierre, I want quality," Button said. "I don't need four picks and three prospects, which two are B and one is an A. I'll take your first-two-round picks and two A prospects. They're going to be in the National Hockey League. Maybe Taylor Raddysh can turn into a Mark Stone (Senators wing and alternate captain)."

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It hasn't been Yzerman's M.O. to sell the farm at the deadline, or at any other time. When Yzerman acquired defenseman Braydon Coburn at the 2015 deadline, he shipped a first- and a third-rounder to Philadelphia, but he also had a surplus. Plus, Yzerman wouldn't have made the deal had he not been able to recoup two second-rounders in the Brett Connolly trade the same night to Boston.

The Lightning probably couldn't keep Karlsson long term. He can be an unrestricted free agent in 2019 and likely will demand between $10 million and $12 million a season for his next deal. Tampa Bay already has to prepare for big extensions for Nikita Kucherov, Andrei Vasilevskiy and Point the next two years.

What complicates a Karlsson trade further is that the Senators would reportedly prefer their trade partner to take on the contract of forward Bobby Ryan, who is due $7.25 million annually through 2021-22. That would be a nonstarter for Tampa Bay, unless it could get a third team to become part of a trade.

Karlsson isn't Tampa Bay's only option. It is still believed to be in on Rangers defenseman Ryan McDonagh, who also has one year left on his contract ($4.7 million). McDonagh has a 10-team no-trade list, but the Lightning isn't on it.

McDonagh won't come cheap, but the price would be less than Karlsson's, maybe a first-round pick and a good prospect, Button said. There's also Red Wings defenseman Mike Green, a rental who could likely be acquired for a second-round draft pick plus other considerations. Columbus left-shot defenseman Jack Johnson also is a potential fit.

It feels like the Senators are considering moving their franchise player in the next few days.

And the Lightning has as good a shot as anyone to reel in the big fish.

Joe Smith can be reached at joesmith@tampabay.com. Follow @TBTimes_JSmith.