And even after his opponents have continued to make offseason moves, he is still confident in his franchise.
"We believe we can win, and I think because of that we should not be afraid to say it,'' Van Wagenen said, according to the New York Post's Kevin Kernan.
"We do believe it. It's just not me saying it. Our players believe it. Our coaching staff believes it, and I think that confidence has resonated across all of us and it gives us the conviction to be able to say it out loud."
Even as Manny Machado, Bryce Harper, Craig Kimbrel and Dallas Keuchel highlight the big-name free agents still available on the market, each NL East team has had a busy offseason.
The Phillies, who added catcher J.T. Realmuto on Thursday, acquired outfielder Andrew McCutchen and reliever David Robertson earlier this offseason, and are still in pursuit of Machado and Harper.
The Braves signed catcher Brian McCann and third baseman Josh Donaldson, and have also been targeting another bat to add to their lineup. And the Nationals added Patrick Corbin for their rotation, Trevor Rosenthal for their bullpen and second baseman Brian Dozier.
"I hope that our division is the most competitive in baseball," Van Wagenen said, "because we are not going to be afraid to go toe-to-toe with any of them and we expect to win, and if we win in this division there is no stopping us.''
And still, the Mets have also been active in Van Wagenen's first few months at the helm.
Since being named general manager in late October, the Mets traded several top prospects to the Mariners for Edwin Diaz and Robinson Cano, brought back Jeurys Familia and signed Wilson Ramos, Jed Lowrie, Justin Wilson and Devin Mesoraco.
"I think we had a number of clear areas of improvement we needed to make, and we were very vocal about what those areas were and we were methodical about trying to address them," Van Wagenen said. "So now that we have done that, we feel really good and really confident about the club that we've built and the players that are here, and we're looking forward about going to war."
Fangraphs projects the Mets to win 85 games this season, six games fewer than the Nationals and three more than the Braves and Phillies. Rotochamp has the Mets winning 88 games, second to the Nationals (90) but more than the Phillies (84) and Braves (82). Baseball Prospectus also has the Mets finishing with 88 wins, one fewer than Washington, two more than Philadelphia and four more than Atlanta.
But Van Wagenen isn't focused on the projections. He's focused on the team going out on the field and winning.
"We are not going to worry about the weather,'' he said. "We are not going to worry about an injury. We are not going to worry about which one of our competitors sign another free agent or trade for another player. We are going to control what we can, and we are going to commit to it every day. We have conviction with everything we do.
"We expect to be good and the other part is we are not going to put anybody on an island. We are not looking for scapegoats.''