The Portuguese defender struggled to break into Pep Guardiola's team in the 2019/2020 season after arriving from Juventus, but last season, he won the plaudits for his creativity at left-back.
However, Kyle Walker's return to form and Oleksandr Zinchenko's reliability ultimately saw Joao Cancelo back on the bench for the end of the season - including the Champions League final.
Barcelona may now be trying to capitalise on the defender's potential discontent at Manchester City, and are aiming towards an "FFP swap" deal, say Castles.
Two players have been offered to Manchester City - Sergi Roberto represents a like-for-like swap, but France international Ousmane Dembele has also been made available and offers the Premier League side to strengthen in attack.
Dembele has failed to live up to his huge price-tag since signing for Barca in 2017, but at 24, perhaps Pep Guardiola could be tempted to try and develop the pacey forward.
It is not yet known if Joao Cancelo would be keen to leave the Etihad Stadium this summer, or if he wishes to fight for his place.
However, it is easy to imagine he could be tempted to follow in the footsteps of Eric Garcia and Sergio Aguero by signing for the Catalan side, should an offer be accepted.
As for Manchester City's interest in the deal, Pep Guardiola would likely prefer a straightforward swap involving Sergi Roberto, especially as he is already in the market for a marquee forward, with Harry Kane and Erling Haaland the two most likely candidates.
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