BRENDAN Rodgers has warned Celtic that the day they become comfortable is the day he will be finished as manager of the club.

The relationship between Rodgers and the Celtic board has appeared strained in recent days after the manager admitted he was disappointed with what had been delivered to date during the summer transfer window, and news last night before the home draw with AEK Athens that target John McGinn had opted to join Aston Villa from Hibernian appears to have done little to ease those tensions.

That has led to questions about the Celtic board’s ambition matching his own, and when asked if he would leave the club if they stopped pushing to be better, Rodgers said: “Yeah. My job is done then. Terminado. Gone.

“But that’s the challenge. You have to test yourself to the limit. You have to be courageous as a club.

“It’s a joy to work here. I love my life here and enjoy being the manager here. But it’s no good if I just sit back and get comfortable. Being comfortable is the enemy of progress.

“I never allow it in my own life or professional life. You see it in sports and in industry. The minute you think you’re doing okay it can quickly disappear, and that’s the greatest institutions.

“You have to be mindful of that and keep getting stronger and stronger.”

While respecting the financial limitations that the club are working under, and understanding the need for financial prudence from the board, Rodgers also said that he is wary of the rot setting in on Celtic’s progression if they don’t invest in quality players as he strives to take them to the next level.

“Dermot [Desmond], Peter [Lawwell] and Ian [Bankier] all want what’s best for Celtic. Critically, they are major shareholders and run the club. I have to respect that, and I do.

“My ambition is for Celtic. Every manger is ambitious but for me it’s inherently about the club. We’ve done a double treble, been invincible in one of those seasons, set a British record for unbeaten games.

“We don’t want to stand still. How do we improve? We improve in Europe and in order to do that, it’s simple, it’s quality players.

“The minute I start thinking otherwise and get comfortable, then progress stops. In football you can’t afford to do that.

“It’s too late once the rot sets in. It’s too late. I’ve always tried to guard against it. Especially after our first season, we built on it last year. We want to keep building it.

“I totally respect how difficult it can be, the financial side is tough at times.”