Sergio Aguero wrote himself into Manchester City's history books when he scored that last-gasp goal to secure the Etihad club their first ever Premier League title in 2012.
That historic goal was the 23rd time he found the net in his debut season, and it was clear City had bagged a real talent. You would expect big things from a £38 million man, but Aguero has excelled as City's 'go-to' man, having scored 84 goals in just 128 Premier League appearances.
Agueroooooo! The title-winning goal that made a man called 'Kun' a City icon (YouTube)
The Argentine's fantastic form last season sparked rumours of a potential move to Real Madrid this summer.
City fans sighed collectively in relief when such a deal failed to materialise. But it is becoming increasingly clear that Aguero needs to move to one of La Liga's two superclubs if he desires greater success.
This isn't to suggest City are a small side or to belittle their recent achievements. But can the blue half of Manchester claim their club shares the stature of Barcelona or Real Madrid?
Aguero's haul in England includes two Premier League titles and a League Cup winner's medal. And few would be surprised if he won a third Premier League title this season. For City are the clear favourites, having strengthened their squad by making big money moves for the likes of Raheem Sterling, Kevin De Bruyne and Nicolas Otamendi over the summer too.
Yet, it doesn't change the fact that a move to his potential Spanish suitors would provide the Argentine with so many more opportunities. For thirteen of the fifteen players to be placed in the top three positions of the FIFA Ballon d'Or in the past five years plied their trade with either Real Madrid or Barcelona. Aguero would surely gain greater personal exposure and win more trophies if a transfer does materialise.
Aguero could challenge compatriot Messi for the FIFA Ballon d'Or with La Liga move (Barcelona FC)
Amid speculation prior to his recent injury, Aguero has stated that his desire to remain at the Etihad until City had secured a Champions League title with the club. Romantics will claim such loyalty is commendable. But others will argue that the Argentine has been foolhardy - even myopic in his thinking.
Although the Citizens have certainly improved in recent seasons and are now expected to reach the knockout stages each year, there is still a gulf in class when compared with the La Liga giants. They were easily beaten 4-1 in 2013/14 by Barcelona, and 3-1 last season by the same club. Chelsea proved back in 2012 that the impossible is possible, but few City fans would claim they will win the Champions League any time soon.
A dejected Aguero looks on as Barcelona put City to the sword (Manchester City FC)
Despite their attacking prowess in the Premier League, City appear incapable of breaking down Europe's elite. This may be down to a lack of quality, or simply a lack of experience. But even such philosophical speculation cannot hide the fact that it would be a huge surprise if they did win the Champions League.
Now aged 27, Aguero is entering his prime. However, such years are double-edged as it also means that the later stages of a player's career are around the corner when skills fade and ambition dulls. If Aguero opts to stay in the Premier League for another few seasons, he will undoubtedly waste the best years of his career in a side that cannot give him what his rich talent deserves.
Barcelona's Luis Suarez made a brave move to the Catalan giants at the same age despite being revered at Liverpool. The Uruguayan icon took a risk and he is now reaping the awards for his star has soared even higher.
Aguero needs to copy Suarez and challenge himself (Daily Telegraph)
Since there is no room in Barcelona's eye-watering attack of Messi, Neymar and Suarez for a fourth South American superstar, a move to Real Madrid would be the most likely destination for Aguero. And Aguero would be familiar with the country's capital having played at rivals Atletico Madrid for five seasons.
Alongside Cristiano Ronaldo and Gareth Bale, his self-imposed ceiling would be gone. And then nothing would be unachievable for the Argentine.