Vanek said he didn't sleep Sunday night after being told about the trade. He practiced with the Islanders on Monday morning, taking Moulson's spot on the top line alongside captain John Tavares and fellow forward Kyle Okposo.
The Islanders took a risk with the trade, hoping that in the time Vanek spends with his new team he can convinced to make a long-term commitment to stay. No negotiations have started yet, and no conditions regarding Vanek sticking with the Islanders were included in the trade.
"I haven't gotten that far," Vanek said. "I didn't sleep at all last night, so I want to catch some sleep first, get to know these guys, and figure it out later."
Vanek saw the writing on the wall with the Sabres, who dealt Jason Pominville last season, changed coaches, and also could trade away veteran goalie Ryan Miller this season. Buffalo had four teenagers in its lineup for its last game and appear a long way off from competing for a championship.
The Islanders returned to the playoffs last season after five years on the outside. New York was knocked out in the first round by Pittsburgh, but showed signs of being on the upswing.
With an eye toward Brooklyn, where the Islanders will move in two years, the club is trying to make strides toward greater improvement leading up to that relocation.
If Vanek can mesh with the young Tavares as well as Moulson did in recent years, and then sign a new deal, the Islanders would have a potent punch up front.
"I want to win," he said. "You train all summer long, practice every day, and you want to have a chance. Right now you know that we struggled (in Buffalo). It's hard to win when you do struggle, especially as one of the leaders, but at the same time reality is setting in and I'm happy to be an Islander."