The Australian was asked about Manchester United boss Erik ten Hag losing his position this week.
Given Postecoglou’s Spurs are only a couple of points ahead in the league table, he may be concerned about his own standing.
He told reporters: “I've, and it's easier to say, never worried about job security. I think if you do you're probably going to end up not doing the role the justice it deserves for yourself more than anything else. The reality is there is no job security. I don't know what job security looks like. What is the average tenure of a manager these days?
“If you think I'm going to be around for five years that is highly unlikely. If you worry about those things and I think you end up chasing your tail a little bit and probably making decisions for the wrong reasons. As I've said before, I understand I won't be here forever but I work as if I will be and I 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.
“Job security for managers does not exist as there is always something that unless you win it and you win it in the right style with the right decisions, everyone else seems that will be under scrutiny so you've got to understand that is part of the role.
“Not that there is anything wrong with that as I think criticism and scrutiny is healthy. Even criticism and scrutiny that is not valid is useful because that is what tests your resolve in doing what you do because if you just jump up at the first time somebody questions what you do then it probably means you do not believe in it.”