City Football Group and Major League Soccer were careful not to draw too many lines of association upon announcing the league’s 20th franchise back in May 2013. New York City FC, they said, would be “a transformational development that will elevate the league to new heights.” Their inception would create “an intense crosstown rivalry between NYC FC and the New York Red Bulls that will captivate this great city.” Manchester City, the European superpower anchoring the purchase, were barely mentioned.

Joe Hart, present for the announcement in Manhattan, gave the game away, though. He was Manchester City’s No1 goalkeeper at the time, and his attendance was symbolic of the relationship many thought would exist between the Premier League giants and their new American outpost. NYC FC, it was perceived, would be their feeder team.

Nearly four years have since passed, with New York City FC having now completed two full seasons as a MLS franchise. Sergio Agüero has yet to play for them, neither has Tommy McNamara been offered a trial at Man City. Pep Guardiola probably couldn’t name NYC FC’s starting lineup. But with the news that a group of NYC FC players, including Costa Rican left-back Ronald Matarrita, are training with Guardiola’s side this month there is a link of sorts to be examined.

This comes after five NYC FC players (Kwadwo Poku, Patrick Mullins, Tony Taylor, McNamara and RJ Allen) spent the off-season training at Man City last year. The two clubs haven’t quite been swapping players like roommates exchanging Netflix passwords, but there has been greater correlation between the two than either franchise would perhaps readily admit.

Of course, it should be pointed out that Man City are not New York City FC’s parent club, nor are NYC FC their feeder team. The two clubs come under the larger City Football Group umbrella, which also includes Melbourne City of the A-League and Japanese outfit Yokohama F Marinos. All three are independent of each other, with their own squads, their own budgets and their own cultures.

But there most certainly has been overlap. David Villa, for instance, spent two months at loan at Melbourne City to keep up his fitness before joining up with NYC FC for the start of the 2016 season. Patrick Vieira left his post as head of Man City’s elite development and under 21s manager to take up the role as NYC FC head coach last year, and of course Frank Lampard delayed his arrival in New York for one last bite of the Premier League with Man City.

And now Matarrita is said to be interesting the Premier League side, with Guardiola in desperate need of depth in the full-back positions. The Costa Rican is still a raw talent, despite an impressive breakthrough year with NYC FC, but the 22-year-old possesses all the attributes to suggest the speculation linking him with a move to Man City might have weight.

However, such a move would present a sporting dilemma for NYC FC. Being under the City Football Group banner has undoubtedly given them the kind of clout they would have struggled for as an expansion team on their own. Without Sheikh Mansour’s financial might Andrea Pirlo, Lampard and Villa probably wouldn’t have pitched up at Yankee Stadium.

But such benefits come with a caveat. NYC FC might deny that they are under any obligation to sell their best players to Man City, but given that both clubs exist under the same ownership, would City Football Group really tolerate a truly world-class talent joining another team, particularly if that team were a rival to Man City?

Matarrita is far from a world-class talent, but were he to make the move to Man City from NYC FC it would raise questions over the true relationship between the two clubs. Are the latter fated to be always be at a competitive disadvantage because of their ownership and the natural order within the City Football Group? Is that worth the benefits that come as part of the arrangement?

This kind of discussion will only become more and more common in soccer, with City Football Group admitting their intentions to expand their portfolio beyond the four clubs they already own. “I would say when the opportunity arises – and we are looking at opportunities – you can expect us to add to the number of clubs we have already within the organisation,” Manchester City chairman Khaldoon Al Mubarak admitted in an interview last year. “It’s too early for me to pinpoint. We are looking at opportunities, we’ll see how it goes. At the right time, the right place, we will tell you.”

Red Bull, another company with a MLS presence, are also reportedly looking to stretch their reach across the sport. The energy drink brand already owns the New York Red Bulls, Red Bull Salzburg and RB Leipzig and now West Ham, Charlton Athletic and Swindon Town are supposedly on their radar. It could be that soccer eventually tightens up its rules on ownership of multiple clubs in order to eliminate conflicts of interest, even between clubs on different continents registered to different associations, but for now this is fair game.

City Football Group did not reply to a request from the Guardian on clarification of the relationship between Manchester City and NYC FC. Matarrita is training in England this month, along with a few other NYC FC team-mates, but the true nature of the process that took him there is far from clear. Not that anything toxic or malicious is to be expected but when one team is defined so profoundly their link with another, these things matter. It matters why Matarrita is training with Manchester City as a New York City FC player.