Tottenham without captain Son Heung-min and Wilson Odobert for Manchester City clash
Son, who felt sore in his hamstring after scoring in a 4-1 win over West Ham United this month, was left out of last week's Europa League clash with AZ Alkmaar and then missed a 1-0 Premier League loss at Crystal Palace on Sunday.
Odobert, who was out of action for more than a month due to a hamstring injury, returned as a substitute in the 1-0 win over Alkmaar but Postecoglou said the winger has suffered a serious setback in the "same area".
"Son is almost fit but probably from our perspective, we'll aim for the weekend. We're quite confident he'll be right for the weekend," Postecoglou told reporters.
"The only other one missing out which is a bit of a disappointment is Wilson, who has had a setback during the week and it seems like it is a serious one so we're just waiting for more information.
"From the weekend everybody is okay and Djed (Spence) is back training."
Spurs, who had a run of five wins in a row before their loss at Brighton earlier this month, couldn't score against Palace but Postecoglou believed persisting with the principles and maintaining consistency can bring them back to winning ways.
"The players and everyone was disappointed with the way things went for us at Palace, both performance and outcome, but we've got to get away from these reactions and try to atone for something," Postecoglou said.
"Part of the process for us is to make sure in every game we stick to our principles irrespective of what has happened in the past."
With Manchester United sacking Erik Ten Hag, Postecoglou said "there is no job security" and he is working hard to bring success to Spurs while he is there.
"I understand I won't be here forever but I work as if I will be and make decisions that will get us to be a successful club.
"If you deviate from that then the inevitability is the end will probably come sooner than you want," he added.