The 59-year-old has overseen one of the worst Premier League seasons in Spurs’ history, sitting in 14th with just 37 points from their 31 games.
Tottenham still have the opportunity to qualify for Europe, however, as they prepare to face Frankfurt in the Europa League quarter-final on Thursday.
Speaking to the press ahead of the game, Postecoglu claimed there is a ‘general sentiment’ that he will leave the club in the summer regardless of what happens.
Postecoglou said: "I think that feeling exists, but not because of that (proving people wrong).
"I don't think that's a healthy motivation to have because ultimately you can't win that contest. I just think we're in that position that the good stuff we may do is going to be turned into a glass half full rhetoric and from that perspective I don't think that can be a driver in what we want to do.
"The lads are really keen to bring success to the club, keep driving the principles of what we started this whole journey with, in terms of the football we want to play, really stick together as they have through the toughest of periods and hopefully we've worked our way into a position where we can make an impact on our season, a really disappointing season for us.
"I just think there's a real determination to take the opportunity that they've earned at this point. I don't think you're going to win that argument of convincing people. I think John (Cross) wrote that even if we win it, I'm gone anyway. That's not having a go at you, that's just saying the general sentiment of people. So if you're trying to use that as a motivation, you're not going to win that anyway.
"There's got to be more in it for us and for us what is the most important thing as a group is that we've been through a really tough time but we're still in a position where we can make an impact and you don't know how often you get those opportunities.
"We're in a quarter-final and I don't know how many times the club has been in a quarter-final in European competition. You don't want to let that slip you by or have the wrong mindset going into it. I think the players are handling it well in terms of how they're trying to embrace this challenge. They're going to face a top team but they have the capabilities to overcome that."