The Islanders also are in a rebuilding process as they look to improve on last season when they reached the playoffs and provided a challenge to the Pittsburgh Penguins in a six-game, first-round series.
New York has been up and down early this season, going 4-4-3 in its first 11 games, including 2-2-3 at home.
While the Islanders are losing a fan favorite and key linemate for captain John Tavares in Moulson, they are adding another proven star and goal scorer to play with Tavares.
Moulson has led the Islanders in goals in three of the past four seasons. Vanek has scored 40 goals twice and was an All-Star in 2009.
Vanek led Buffalo in power-play goals in seven of his nine NHL seasons and topped the league with 20 in the 2008-09.
In 36 career playoff games, Vanek — the No. 5 pick in the 2003 NHL draft — has 15 goals and five assists.
"Thomas is one of the top proven scorers in the National Hockey League, but with his unrestricted status, Matt comes in. He has six goals and is off to a good start and plays in the hard areas and on the power play and will continue to contribute in that regard," Regier said. "I think this is more an overall deal that will improve this hockey club moving forward."
This trade came at a particularly curious time as chants of "Fire Darcy!" have been directed at Regier during recent home games.
"Is it a bigger challenge? Yes," Regier said when asked if he is feeling more pressure now in his job. "I'd substitute the word challenge for pressure. You can't operate. If you're under so much pressure, it's paralyzing.
"You have to find and get good players and build around that."
Buffalo will host the Dallas Stars on Monday and their new coach Lindy Ruff, the winningest coach in Sabres history, who was fired in February and replaced by Ron Rolston, whose job also isn't safe.
"It's part of the business," Rolston said of Ruff's dismissal and return. "Coaches change jobs. He did great things for the organization, and I'm sure they'll have something for that.
"We've got bigger things to focus on ourselves. Worry about things that we can have control over."
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