Sanchez's second-half introduction immediately changed the dynamics of the match, and it was the Chilean's through pass that found Welbeck in the box to get the Londoners a goal back. With the right personnel (preferring Matic to Cesc Fabregas, dropping John Terry and re-intoducing Victor Moses to the side) the team was transformed into odds on favourites for the Premier League, with an impressive sequence of victories.
Which brings a different emphasis.
The Gunners had been quite pedestrian in the first-half, with Olivier Giroud's header in the 21st minute stretching Mignolet, but nothing apart from that and Wenger was forced to send Sanchez on in a bid to spark some life into his side.
"Nothing happened, nothing at all", Wenger told reporters at Arsenal's London Colney base, after shaking Sanchez's hand in front of the cameras before training.
"I think we are the best club in the world and we have to defend the pride of it", said Wenger. However, I'm going to go out on a limb and say that Leicester's two wins in as many games may not have been entirely due to Craig Shakespeare's special talents.
"What we did have at Chelsea is a very strong dressing room".
Sanchez has been involved in 26 goals in 26 Premier League games this season - scoring 17 and providing nine assists.
Wenger also described his relationship with Alexis, which has been reported as fractious, as "honest and normal, like with every single player". Perhaps the purist will argue a long-ball game is required against Bayern too.
Craig Burley can not wrap his head around why Alexis Sanchez would sign a new deal as Arsenal are trending backwards.
Germany's Mesut Ozil and Chile's Alexis Sanchez are apparently playing hardball with Gunners manager Arsene Wenger and delaying their decisions on respective new contract extension offers from Arsenal.
His argument that it is not just about the individual included an attempt to illustrate that Arsenal's fortunes do not depend on the Copa America victor.
That Arsenal improved drastically with Sanchez on the field - he set up Danny Welbeck for Arsenal's goal that made it 2-1 - will be all the more galling to Arsenal's increasingly disgruntled fan base. You can understand that sometimes people lose a little bit of patience but we can't. Saturday: Eibar 1 (Ruben Pena 72) lost to Real Madrid 4 (Benzema 14, 25, Rodriguez 29, Asensio 80); Barcelona 5 (Messi 24, 63, Neymar 40, Rakitic 57, Umtiti 60) bt Celta Vigo 0.
When the rest of the squad had finished the session, one player, who has not been named by the BBC, had to be held back from physically engaging Sanchez as tempers flared once more.
It seems to irritate him that Sanchez has been exonerated amid the inquests into Arsenal's struggles in defining fixtures.