Spurs (short for Tottenham) took the lead against Arsenal in the 23rd minute through Son Heung-Min. But they went into the break 2-1 down after Solanke scored an own goal and Leandro Trossard added another for Arsenal.
Postecoglou made two changes at half-time, bringing on Pape Matar Sarr and Yves Bissouma for James Maddison and Brennan Johnson, but it was not enough to get Spurs back into the game.
The defeat left Tottenham down in 13th place in the Premier League table and after the match, Postecoglou did not hesitate to criticise the team's performance.
"The team didn't play well, especially in the first half. We were too passive, we let Arsenal control the game. Really disappointed with the way we played without the ball. The players let the opposition dictate the tempo and that cost us.
Tottenham did not play to their character. We are very aggressive with and without the ball, but tonight in the first 45 minutes we were too passive. That is unacceptable,” Postecoglou said after the match.
Postecoglou did not notice the controversial moment in the first half when Arsenal equalised from a corner, but it should have been a Tottenham goal kick. "I don't want to talk about the referee. Tottenham were in a position we didn't want to be in," the Tottenham manager stressed.
Postecoglou gave 18-year-olds Archie Gray and Lucas Bergvall the full 90 minutes, hoping they would learn from the loss.
“We have lost too many games this season, which is unacceptable to anyone at the club. I have made big demands on players like Archie and Lucas, but I hope they are as hurt as anyone else not being able to perform on such a big day,” Postecoglou concluded.
