Spurs were unable to get a win against Rangers in the Europa League group stages.
They had to battle for a 1-1 draw, with Dejan Kulusevski equalizing in the second half.
“We’re in a fight here,” said Postecoglou post-game.
“I’m not going to go around worrying about people’s bruised egos. We’re here to achieve things. We are down to the bare bones in players. If there’s somebody in the dressing room who’s fit who feels he needs something extra in this moment, he’s probably not the right type.
“I need guys who understand the situation we’re in. We’ve got 15 fit players, in some positions we’ve only got two players. I’m not going to go around trying to get extra out of people. If they’re not able to give extra now, it gives me an indication of when they’re at.
“We're in a fight here, in a battle. When people are in a fight and a battle do you think they go around asking “How are you feeling today? Are you feeling up for this?” You've got no choice, mate. You've got to be up for it.
“It's not about Timo. It's about who we are in the situation we're in right now. If it's not Timo it could be someone else on Sunday (against Southampton).
“If somebody else doesn't perform to the levels for the current situation we're in then we're going to suffer for it because we've only got a certain amount of players.
“It's not about bringing somebody down and blaming someone. It wasn’t criticism, it was an assessment.
“This is not about one person, it's what we're in and the situation we're in right now. We've got a limited amount of players, we're really stretched but we've got big games that can set up our season.
“It's a great challenge. I want people who are up for that challenge and when they go out there, irrespective if things go well or not, I want them relishing the opportunity to be out there.
“This is not a time for us to be kind of worried about people's mindset. If you don't understand or feel what we're in at the moment, I'm not sure what it's going to take.”