THE defining moment of Middlesbrough’s season was not a goal. It was not a sublime piece of skill, a save from Darren Randolph or even one of the many misses that ultimately proved so damaging to the club’s promotion hopes. It wasn’t even the point at Rotherham’s New York Stadium when news filtered around the ground that Derby County had reclaimed the lead.

No, the moment that defined Middlesbrough’s season was a substitution. With his side 1-0 up in the 62nd minute of March’s home game with Brentford, Tony Pulis took off Britt Assombalonga and replaced him with George Friend. Boro went on to lose 2-1, sparking a six-game losing run that saw them tumble out of the top six, but the impact of Pulis’ move was more far-reaching than simply affecting the outcome of a solitary game.

It was the point at which his relationship with Middlesbrough’s supporters became broken beyond repair. It is also the reason why he should stand down as manager and allow someone else to spearhead next season’s promotion push.

Middlesbrough have failed under Pulis this season, but their biggest failing has not been on the field. While the 61-year-old’s moans about financial constraints and a need to balance the books have become tiresome in recent weeks, they are not without a degree of merit. Players have been sold, he has helped raise around £40m and the wage bill has come down significantly from where it was in the immediate aftermath of relegation.

There are counter-arguments to Pulis’ pleas of poverty – the £20m that was spent on Aden Flint, Paddy McNair and George Saville can hardly be regarded as good value and Boro’s wage commitments are still understood to be significantly larger than those at either Norwich or Sheffield United, the clubs that won automatic promotion – but finishing seventh is probably a fair reflection of where the Boro squad stands in relation to the rest of the division.

In different circumstances, you could argue that the club was well set to kick on next season, and that continuity of management would be a plus. However, that would be to ignore the massive disconnect that has built up between Pulis and the Riverside faithful.

Middlesbrough’s fans just about tolerated Pulis’ continued presence in the dug-out while promotion remained a possibility, but their support came under duress and there will be no such leeway granted if he remains in charge next season. If he meets Steve Gibson and opts to trigger the one-year extension that is written into his contract, he will be a dead man walking from the word go.

Why? Results play a part, but the unhappiness goes much deeper. It is a comment on Pulis’ entire footballing philosophy, hence the vitriolic reaction to Assombalonga’s departure for Friend a couple of months’ ago.

Turning up to watch Pulis’ team play at the Riverside has become an act of duty rather than enjoyment. You know what you are going to get – five defenders strung along the back, a couple of holding midfielders playing in front of them, and a deeply conservative mindset that means you immediately sit back and attempt to protect what you have if you happen to find yourself in the lead – and it jars with what football is supposed to be about.

The days when supporters would loyally turn up to support their team with little or no expectation of entertainment are long gone. In the pre-social media world that Pulis loves to hark back to, you were born a Middlesbrough supporter and that identity trumped all other considerations. If you wanted to watch football, you had to go to Ayresome Park.

Now, Boro fans can watch football from all over the world, any hour of the day. Instead of going to a Tuesday night game at the Riverside, they can stay at home and watch the Champions League. If they want to keep half-an-eye on how Boro are doing, they can flick over via Sky’s red button. And if they do decide to pay their money and head through the turnstiles, they expect to be entertained. Or at the very least, not to be sent into a slumber.

Pulis will no doubt claim that his job is to win football matches – to quote Alan Durban, another former Stoke boss who hailed from Wales, “if you want entertainment, go and watch the clowns” – but this week’s thrill-a-minute Champions League matches have further underlined just how dull life at the Riverside has been this season.

Far too many games have been featureless, safety-first encounters, with Pulis setting up his side to be hard to break down rather than looking to take the game to the opposition. Maybe if so many chances had not been missed, the perception of matches being stultifying and dull would not have taken hold, but the reality is that Middlesbrough’s supporters have made up their mind.

They do not want another nine months of watching a Pulis side trying to grind its way to promotion, and whatever the current boss does or does not do if he is to remain in his position, he is not going to turn that around. He is not going to suddenly abandon his managerial DNA and adopt a completely different philosophy, so if he remains in place, he will be in the eye of a storm from the first very weekend of a new campaign. Even if a Pulis-led Boro were to win their first four home games of next season, the minute they went behind in game five, cries of “We want Pulis out” would start ringing around the Riverside.

That situation is simply not tenable, and Pulis himself must see that his continued presence in the dug-out would be a hindrance rather than a help when it comes to trying to repair the bonds that have become badly frayed in the last 12 months.

He bridles at the accusation he is a “footballing dinosaur”, but whether he likes it or not, a large proportion of Boro’s fanbase sees him in that light. He has worked manfully in the last 18 months, trying to keep his side in the promotion picture while also cutting costs, but has lost the support of the people he needs most. Once the fans have turned, the end is always imminent.