First-half goals from Fred Onyedinma and Garath McCleary gave the visitors a two-goal lead while Jason McCarthy added a third in the second half from a corner.
Boro failed to register a single shot on target at the Riverside on an afternoon Warnock will want to forget.
The result means Boro finished 10th in the Championship table, 13 points off the top six.
Warnock will now hope for a productive summer transfer window, when he’s looking to sign ‘eight or nine’ new players to bolster his squad.
The Boro boss will also hope the players who are currently missing through injury, including Dael Fry, Marcus Tavernier, Anfernee Dijksteel and Sam Morsy, will be available for the start of pre-season.
Here’s how Boro fared against Wycombe at the Riverside.