Per SNY's Andy Martino, the Mets and Yankees had a tentative agreement in place for Wheeler that wound up falling through because of medical concerns about another player in the deal.
Martino was unable to provide additional details about what the entire deal would have included but did note general managers Brodie Van Wagenen and Brian Cashman had "intensive discussions" about other players besides Wheeler.
Wheeler was one of the most-discussed players on the trade block last summer. The Athletic's Ken Rosenthal reported on July 30 that the Oakland Athletics, Tampa Bay Rays and Atlanta Braves had "varying" levels of interest in the right-hander.
The Mets ultimately held onto Wheeler for the remainder of the season. They played well over the final two months with a 33-21 record but ultimately finished three games behind the Milwaukee Brewers for the second wild-card spot in the National League.
The Yankees ultimately didn't add a starting pitcher before the trade deadline, though they still won the AL East with 103 wins and advanced to the ALCS before falling to the Houston Astros in six games.
Wheeler wound up leaving the Mets in free agency this offseason when he signed a five-year deal with the Philadelphia Phillies.
Cashman ultimately landed an ace this offseason by signing Gerrit Cole to a nine-year, $324 million deal, the largest deal ever given to a pitcher in MLB history.