Nathan Ake’s 88th-minute winner was City’s first-ever goal at the Tottenham Hotspur Stadium and knocked Spurs out of the FA Cup at the fourth round stage.
For Tottenham, attention now turns to the Premier League, where they sit fifth, eight points off leaders Liverpool.
“We fought hard to stay in the game, but to be honest that’s all we did is stay in the game”, said Postecoglou. “Our second half was OK. First half was a little too passive and we allowed them to get a bit of rhythm in the game.
“We started the second half with a bit more conviction about our play. But, like I say, we were working so hard to just stay in the game, and that wasn’t going to be enough tonight. You need to put pressure on the opponent from the first minute, and we didn’t do that today.”
He added: “It’s about just having a bit more belief and conviction in ourselves for the first 45 minutes. I thought we defended well. It’s not like Vic had a million saves to make.”
Postecoglou said of Pep Guardiola’s side: “They are a top team. They are the benchmark, and we’re not there yet. They’ve got about eight or nine years on us. It’s not an excuse, but the reality of it is they’re well down the line being the team they are, and we’re still very much in the early stages.”
When asked whether he was tempted to start Maddison against City, Postecoglou replied: “Not really. Knowing the nature of the game today, he’s trained the last week and a half. We could give him some minutes today, which we did, and he should be alright to go from now on.
“We need him and others to pitch in. It wasn’t really much of a dilemma whether to start him or not. I felt coming off the bench today was going to be better for us as a team, more than anything else.”