You can imagine the reaction then when Arsenal's superstar Chilean Alexis Sanchez was named on the bench for the match - cue Piers Morgan.
Wenger tried to rectify his mistake at half-time by sending on Sanchez for Francis Coquelin and, after Giroud's header was tipped on to the crossbar by Simon Mignolet, the Chile global made his mark. "My only regret is that we lost the game".
Wenger's decision to drop 20-goal Sanchez in favour of Olivier Giroud because he wanted to be more direct and strong in the air appeared to have an immediate - and detrimental - effect on his side.
"The thinking was that we had to go more direct and I wanted to play two players who were strong in the air because we made a decision to go more direct".
Alexis Sanchez started Saturday's game behind Arsene Wenger on the bench rather than on the pitch. Arsenal paid a predictably heavy price for Wenger's stunning gamble, delivering a flat performance in the first half of the 3-1 loss. Wenger admitted his mistake and accepted responsibility afterward.
"Everybody will come to the same conclusion, but I'm strong enough and lucid enough to analyse the impact". I believe it's the same for every player. Francis Coquelin, will court further criticism for a below-par performance which only adds to those who want him dropped from the starting XI, while £35million man Granit Xhaka continues to look like a player going through the gears - unable to assert his influence on another big game although he was unlucky to pick up a yellow card in case of mistaken identity. "This decision was not easy to make, but I have to stand up for it".
The result isn't crushing in itself, but Sanchez-gate could alter the trajectory of his and the manager's future with the club. Wenger is expected to determine his Arsenal future before the end of March.
It was only the Reds' second league win of 2017, the other coming at home to Tottenham, but extended Jurgen Klopp's record against his top-six rivals to 19 points from nine games this season.
And we'll always know how the longtime Arsenal boss feels about it.