With Mesut Ozil left behind in London as he recovered from the flu Wenger stunned the travelling Arsenal fans by leaving his side’s top scorer and highest assist provider on the bench, fielding Olivier Giroud as a central striker.
It appeared the plan had been to beat Liverpool’s press with long balls to the Frenchman but it was scarcely apparent in a woeful first half as Jurgen Klopp’s side cruised into a 2-0 lead in the first half thanks to goals from Roberto Firmino and Sadio Mane.
Sanchez was introduced at half-time for Francis Coquelin and Arsenal immediately improved, the Chilean providing the assist as Danny Welbeck clipped home a fine finish on 56 minutes to bring the visitors back into the game.
Asked on BT Sport whether he had erred in leaving out his star player Wenger said: “Yes but I felt in the first half our strikers suffered from the fact that we didn’t dominate the midfield.
“The second half was much easier because you could see that Welbeck and Giroud were much better than in the first. It’s always debatable that.”
Georginio Wijnaldum added a third for Liverpool in added time after an incisive break that followed Sanchez going close to an equaliser.
Victory for Jurgen Klopp’s men took them above Arsenal into fourth but Wenger refused to concede that his 19 year streak of taking Arsenal into the Champions League might be over.
“It is a possibility to be in it as well so let's focus on that,” the Frenchman said.
Arsenal are currently two points behind Liverpool and Manchester City but hold a game in hand on Klopp's side.