With ex-Manchester United defender Fernandez on a yellow card by this point, Monaco wanted to try and take advantage of the foul by reminding Italian referee, Maurizio Mariani.
Monaco boss Adi Hütter and left-back Krépin Diatta both felt the decision was unfair, with the manager also moaning about a late yellow for Denis Zakaria which rules him out of the second leg.
But IFAB rules state a yellow card can be awarded to a player who: "Argues with the referee or other match official (verbally or by making gestures).".
It was a very unfortunate end to the Libya international's Champions League debut following a loan transfer from Besiktas to Monaco in the winter transfer window.
Mariani then brandished a yellow card but to the 28-year-old instead of the fouling player.
