The deal will pay Marchessault $7 million in year one, $6 million in year two, $5 million in years three and four, and $3.5 million in years five and six, according to TSN's Pierre LeBrun.
The 27-year-old burst onto the scene with the Florida Panthers last season by scoring 30 goals and 51 points in 75 games, which made him one of the most coveted players in the expansion draft.
Marchessault has continued to prove his scoring prowess in Las Vegas, as he leads the Golden Knights with 37 points in 35 games, including 15 goals.
The extension would make Marchessault the first forward to sign an extension with the new franchise.
Shea Weber will be sidelined for the immediate future.
The Montreal Canadiens defenseman is doubtful to return to the lineup until after the Jan. 28 All-Star break, the team announced Wednesday, as he continues to recover from a foot injury.
Weber has missed the last seven games since his previous appearance in a 3-0 loss to the Ottawa Senators on Dec. 16.
On Monday, Canadiens coach Claude Julien noted Weber does not have any broken bones in his foot and that he is simply rehabbing from the injury. Weber was wearing a protective boot as of Wednesday.
The veteran defenseman has tallied 16 points in 26 games this season.
The Chicago Blackhawks may not win the Stanley Cup this season, but they did come first in at least one category.
The Blackhawks' iconic look, worn since 1959, has been named the NHL's greatest uniform, as selected by fans in an NHL poll.
Founded in 1926, the Blackhawks are six-time Stanley Cup champions, including three Cup wins since 2010. The legendary franchise has also been home to a host of Hall of Famers, from Stan Mikita to Bobby Hull and Denis Savard, plus current stars Patrick Kane and Jonathan Toews.
The NHL's ranking included the top 25 uniforms of all time, with every Original Six franchise finding a spot on the list:
Rank
Team
1
Blackhawks
7
Detroit Red Wings
9
Montreal Canadiens
12
Toronto Maple Leafs
15
Boston Bruins
23
New York Rangers
Both the Blackhawks and Toronto Maple Leafs had two separate uniforms qualify for the Top 25 ranking, coming in at 21st and 18th, respectively.
Tuesday's 5-1 loss to the Boston Bruins marked the third straight game in which the New York Islanders have allowed at least four goals.
Through 15 games in December, no team saw more goals against than the Islanders, who allowed at least three tallies in 12 contests. On seven nights, that number ballooned to five or more.
It's obvious the Jaroslav Halak-Thomas Greiss tandem is no longer working. The two have combined for an .893 save percentage, only four points ahead of the last-place Arizona Coyotes.
Tuesday's loss, coupled with a victory by the surging Carolina Hurricanes, bumped New York from a playoff position, an absurd reality considering the Islanders' dynamic offense trails only the NHL-best Tampa Bay Lightning.
Time is running short for general manager Garth Snow to bring in a netminding reinforcement ahead of the Feb. 26 trade deadline. Here are five possibilities worthy of his consideration:
Robin Lehner
With reports indicating the Buffalo Sabres are already taking calls on both of their goaltenders, the Islanders could make a quick deal for Robin Lehner.
For the third consecutive year, the fiery netminder has impressed on a poor Sabres squad. He's posted a .916 save percentage over 30 games, putting him in the same conversation as Braden Holtby, Ben Bishop, and Martin Jones, among others.
Lehner is set to become a restricted free agent at season's end. If things go south, there is no long-term commitment for New York. As it stands, Halak is set to become unrestricted this summer, while Greiss is signed through the next two campaigns.
Jimmy Howard or Petr Mrazek
The Detroit Red Wings could have a pair of goaltenders up for grabs, either of which could be an upgrade for the Islanders.
Despite pundits seeing Petr Mrazek as the Red Wings' goaltender of the future, Jimmy Howard has taken the majority of time between the pipes, and deservedly so. He boasts a .913 save rate through 32 appearances this season; not bad on a Red Wings team that sits ahead of only three teams in the East.
While Mrazek has struggled over the past two campaigns, the 25-year-old netminder still holds potential. He's just two years removed from a 27-win campaign. Only once in the last 10 seasons has an Islanders goalie registered that many victories (Halak, 2014-15).
Michael Hutchinson
Michael Hutchinson had a tough time with the Winnipeg Jets last season, but the 27-year-old has rebuilt his game and his confidence in the minors this year, proving he's ready for another shot at prime time.
Through 18 games with the AHL's Manitoba Moose, Hutchinson has lost just twice while posting a league-leading .947 save percentage. Not only could Hutchinson serve as a potential upgrade for the Islanders, he also comes at an affordable price, as his cap hit stands at just $1.15 million.
Antti Raanta
It'd be odd for Arizona to move on from Antti Raanta after acquiring him in a blockbuster deal last summer - the same trade that brought Derek Stepan to the desert - but all options must be considered for a squad that has occupied the league's basement all season.
When healthy, Raanta has put up respectable numbers in Arizona, as he owns a .912 save percentage through 20 games despite the Coyotes allowing 32 shots a night.
As an added bonus, Raanta could quickly fit into the Metropolitan Division, where he previously resided for two seasons with the New York Rangers, a stretch that saw him post a 27-14-4 showing. Like Hutchinson, Raanta also comes at a cheap ticket, as he's on an expiring contract that carries a $1-million cap hit.
Wayne Gretzky's moved down a couple of lines in the record books.
Two players leapfrogged a pair of The Great One's accomplishments Tuesday, beginning with Los Angeles Kings forward Dustin Brown, who surpassed a mark from Gretzky's time in Tinseltown.
Two tallies against the Edmonton Oilers gave Brown 15 goals on the season, and 247 in total for the franchise that drafted him in 2003. That puts Brown one ahead of Gretzky for seventh all time in Kings scoring.
That nudged Ovechkin one ahead of Gretzky's goal total in Edmonton.
Rank
Player
Franchise
Goals
1
Gordie Howe
Red Wings
786
2
Steve Yzerman
Red Wings
692
3
Mario Lemieux
Penguins
690
4
Joe Sakic
Nordiques/Avalanche
625
5
Bobby Hull
Blackhawks
604
7
Alex Ovechkin
Capitals
584
8
Wayne Gretzky
Oilers
583
The good news for Gretzky fans? Most of his records should be on the books for a while if they don't prove completely unbeatable, like his 50 goals in 39 games, 92 tallies in a single season, and an astounding 2,857 career points.
A 3-0 victory over the Nashville Predators on Tuesday gave the Vegas Golden Knights their 17th win on home ice, the most any team has managed in its own barn this season.
The win also marked Vegas' eighth straight victory and the 13th consecutive game in which the Golden Knights have recorded at least one point.
Here's a look at the five best records on home ice:
Team
GP
Wins
Point %
Golden Knights
20
17
.875
Lightning
20
16
.825
Jets
18
14
.806
Capitals
21
16
.762
Wild
19
13
.737
The upcoming schedule could be a little more difficult for the Golden Knights, as the team plays six of its next eight games away from T-Mobile Arena.