Modern Man City have been shaped by Yaya Toure more than any other player

"[The fans] have to come [to Tuesday's game vs. West Brom] to support more than ever and to express gratitude for one of the most important players in the history of Manchester City ... His impact here was amazing, he was the first player to come here and he helped make this club what it is right now."

Pep Guardiola was speaking about Pablo Zabaleta on Monday, but the words felt equally applicable to Yaya Toure. West Bromwich Albion's visit on Tuesday will be the Argentina international's home farewell and it may yet be the last the Etihad Stadium sees of Toure, too.

So history threatens to repeat itself. Manchester City finished the 2014-15 season against Southampton, knowing it was Frank Lampard's farewell and almost certainly James Milner's. But Toure was also substituted to appreciative applause at a time when Inter Milan were courting him and after his agent Dimitri Seluk had contrived to create a row with the club. The player went nowhere.

Fast-forward to the present, and a now familiar sense of uncertainty surrounds Toure. This season has been notable for the latest Seluk storm. Relations have been repaired by the midfielder, but he is out of contract at the end of the season. The rumours are that City will offer him a deal. Toure has indicated over recent months that his preference is to stay. But there is no guarantee; this could be goodbye.

If so, it will be a happy one. The veteran has made the most of his second lease of life at the club, seeming more appreciative and more open, both relishing and railing against his role as the elder statesman. Raheem Sterling and Leroy Sane have nicknamed him "Uncle Yaya," and the England international cheekily said "Happy 38th birthday" when he turned 34 on Saturday.

Other numbers have a certain pertinence. Toure should make his 298th City appearance across competitions against West Brom, suggesting he could finish up at Watford on Sunday with one shy of 300. If he goes, it will be as a transformative force. The modern City have been shaped perhaps more by Toure than anyone else. Sergio Aguero delivered more goals, including the most dramatic and decisive of all against Queens Park Ranger in 2012. David Silva has been the classiest act and the connoisseur's choice. Vincent Kompany has lent leadership. Zabaleta has offered commitment and unselfishness in unrivalled quantities.

But Toure has been the greatest catalyst of all. If an elite-level player's significance is measured in silverware, Toure has been among the most influential players of his generation. City have won five major trophies in the Sheikh Mansour era. Consider his contribution to each.

The 2011 FA Cup, City's first honour for 35 years, was secured courtesy of Toure's final winner against Stoke City. Arguably more important still was his semifinal strike against Manchester United. His status as their scourge proved pivotal again in 2012, when a first league title in 44 years was won. He was the personification of what City had and United lacked, the man who shifted the balance of power.

Sir Alex Ferguson had showed a strange reluctance to buy central midfielders. United were underpowered in the centre of the pitch. In contrast, Toure represented a rampaging force, one United could not contain: not in their 6-1 thrashing nor, more tellingly, in City's 1-0 win in May 2012, which propelled them into pole position and ended Park Ji-Sung's Old Trafford career. It was Toure, too, who set up the eventual coronation with his late brace at Newcastle in the penultimate fixture.

City's second title came partly courtesy of an historic achievement from Toure, joining Lampard in the select band of central midfielders to score 20 Premier League goals in a season. He symbolised Manuel Pellegrini's ultra-attacking approach. He enabled them to score an English record of 156 goals in all competitions.

Along the way, they also won the League Cup, Toure scoring a long-range equaliser against Sunderland in the final. Two years later, they regained it, Toure converting the decisive penalty in the shootout against Liverpool.

That capacity to prove the big-game player rendered him their talisman. Like City, Toure was rarely at his best on the Champions League stage. Like them, he could be a formidable force in domestic football. Like them, he slowed towards the end of Pellegrini's reign.

He has been emblematic, but also pioneering. Robinho and Carlos Tevez had arrived before him, but Toure was the first superstar to show real longevity. He has been one of the core six, with Aguero, Silva, Kompany, Zabaleta and Joe Hart, to provide continuity and to fashion a new club after the injection of investment and ambition.

He has become a strange symbol of Guardiola's City. The coach has compromised and changed his mind, as Toure's return to favour shows. But he has also prioritised quality, and Toure's reinvention as a holding midfielder is an indication of his capacity to keep the ball. At his peak, he was a rare blend of physicality and technicality. It made him a unique figure; certainly in the Premier League at the time, but also in City's modern history.

That combination of athleticism and ability may mean he is celebrated on Tuesday. Or a City career that has already entered extra time could be extended again, and there may be another farewell in 12 months' time and the long goodbye will continue.