The Seattle Kraken used their exclusive negotiating window with unrestricted free agents to start building their roster ahead of Wednesday night's NHL expansion draft reveal.

Sources confirmed to ESPN that Edmonton Oilers defenseman Adam Larsson has agreed to a four-year, $16 million deal with the Kraken and that Florida Panthers goalie Chris Driedger has agreed to a three-year, $10.5 million deal with Seattle.

Both players will count as Seattle's selections from those teams in the expansion draft.

Another pending free agent, Dallas Stars defenseman Jamie Oleksiak, has also been engaged in talks with the Kraken.

Larsson, 28, has rounded into the kind of defensive defenseman the Oilers hoped he'd become when they made a one-for-one-trade with the New Jersey Devils for Taylor Hall in 2016. There were expectations that Larsson would pair well with Edmonton's newly acquired defenseman Duncan Keith, but Larsson opted for a change of scenery.

Driedger, 27, had a breakout season with the Panthers, going 14-6-3 in 23 games with a .927 save percentage and a 2.07 goals-against average. But with the Panthers having to protect Sergei Bobrovsky in the expansion draft due to his no-move clause, and with top prospect Spencer Knight having arrived on the team last season, Driedger was expected to move on.

The Kraken had an exclusive negotiating window with unrestricted free agents from Sunday to Tuesday. They submitted their expansion lists to the NHL on Wednesday at 10 a.m. ET. The first roster of Seattle Kraken players will be revealed at 8 p.m. ET on ESPN2.