He did not need time to settle in, showing his quality in glimpses.
Fernandes snapped into a strong challenge with compatriot Joao Moutinho and took on the role of free-kick duty.
The midfielder even tested the palms of former Sporting team-mate Rui Patricio with some long range efforts.
He could not help United open the scoring though and get the all important three points.
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But in the second half, he was dropped into a deeper role as United looked to stamp some authority on the game.
Diogo Dalot went closest with a header just wide of the mark in the dying embers.
Mata also had an effort fly just wide of the mark after good work from Aaron Wan-Bissaka.
United failed to capitalise as Chelsea dropped two points at Leicester after their 2-2 draw with the Foxes.
