Barcelona fans are notoriously demanding and, just as with El Clasico rivals Real Madrid, they are not shy in making players aware when they are falling short of their expectations.
Frenkie de Jong knows this all too well; the Dutchman was heavily whistled by disgruntled Blaugrana fans as he trudged off in two recent home defeats against Cadiz and Rayo Vallecano. Barca were chasing a late equaliser in both games but the ineffectual midfielder was dragged off in a clear signal that both Xavi Hernandez - and the club's fans - believed his performance was not helping.
Things have not entirely gone to plan for De Jong since his high-profile €86million (£73.7m) transfer to the Camp Nou from Ajax in the summer of 2019. That deal came off the back of the midfield playing a starring role in the Amsterdam club's Eredivisie success and their stunning Champions League run, which saw them fall agonisingly shy of reaching the final.
It would be wrong to say that the 25-year-old has been a failure at the Camp Nou, despite coming with sky-high expectations and a sizable transfer view. He was viewed as the future of Barca's midfield and the long-term successor to the holes left by Xavi Hernandez and Andres Iniesta.
While that has not played out, his inability to hit the highs are not entirely of his own doing. De Jong's role in Barca's midfield has never been truly defined, with Sergio Busquets the long-term anchor at the base of the three-man unit with the other two roles slightly more dynamic. The emergence of teenage sensation Pedri has ensured De Jong is not the metronome in the midfield that many may have envisaged, while fellow teenager Gavi's all-action and combative style endears him to fans in a way that the Dutchman's more languid approach does not.
Much of the excitement around De Jong's arrival may also have been partly superficial. Most viewpoints were comprised from a handful of starring roles in the Champions League knockout stages, but not enough of a sustained sample size. There is also a prevailing romanticism among many Barca fans that stars of Ajax are able to seamlessly adapt into Barca's style - with both clubs so heavily influenced by Johan Cruyff's principles - which may have distorted views.
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It was under incoming United boss Erik ten Hag that De Jong starred so notably at Ajax. De Jong has been identified as a transfer candidate by United, according to reports in the Catalan press, who claim Ten Hag is hoping he can convince his former player to join him in the Premier League.
While it is understood that such a deal is not as close as suggestions from Barcelona claim, there is an interest from Ten Hag and United in exploring the possibility of a transfer switch. Such a deal would see the two link up alongside Donny van de Beek - who impressed alongside De Jong in that Ajax midfield - at Old Trafford.
United's need for overhauling their squad is well-known with Ten Hag needing to revolutionise the starting line-up, but what better way to start than bringing in De Jong? He has already found the player's best form which has also maximised that of Van de Beek.
Ten Hag has since never hidden his admiration of De Jong, speaking to UEFA.com of his compatriot's talents, he said: "He is always calm and always has the solution. He scans so well that he always knows how to go forward. You can hardly put him under pressure - that is such a great gift."
While United must move away from their previous model of spending big transfer fees on individual players, the signing of De Jong would be part of a clear and coherent thought process on how Ten Hag wants his new side to play - and his availability is a unique market opportunity which the club should look to take advantage of.