Alejandro Garnacho and Kobbie Mainoo were two of four players viewed as untouchable by Manchester United in the summer. Fast forward six months and there is now doubt over that status.

Mainoo is under contract at Old Trafford until 2027 and United do have the option of an additional year, but surprise links to Chelsea have emerged. Garnacho is contracted until 2028 but has been left out of Ruben Amorim's team recently.

Premier League profitability and sustainability rules mean United are forced to sell to raise funds and lower their salary spend. Andre Onana and Rasmus Hojlund were the other two that the club did regard as not for sale but both have endured difficulties this season.

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Mainoo and Garnacho represent pure profit on the books as they progressed through the academy. PSR played a key role in the selling of Scott McTominay to Napoli in August, who United could do with this season.

The high wages at Old Trafford have been a concern for many years. Marcus Rashford's future at the club is currently in doubt but the main stumbling block in any deal appears to be his salary. MEN Sport understands that Mainoo is unhappy with the initial terms offered to him.

One man who will play a big part in the decision making behind-the-scenes is Omar Berrada. After joining from Manchester City as United's new chief executive, Berrada has pressed on implementing the right structure for success to arrive.

A desire to pay the right salary and transfer fee is something Berrada has been keen on since working at Man City. Footage from a documentary at the Etihad Stadium shows the Paris-born in conversation with City's director of football, Txiki Begiristain, about the wages paid for players in comparison to their European rivals.

"In the end, here is about keeping talent, maintaining the balance - and the other viewpoint is salaries," he said. "When you look at salaries, we're high up, but in the end we're sitting fourth in Europe.

"So above us are United; Barca which - they're now cleaning house and lowering (salaries) a little bit; PSG, which they've gone up due to the signing of Lionel Messi.

"And the other thing I would mention is that in the end, what we need to look at is how much this represents versus the revenues. We've always maintained ourselves at 60-61%, which in the end the industry requires in order to be a sustainable club. And we've kept ourselves between these levels.

"We know that when you win, you have the pressure from players and agents, where they're always asking for more salary. You need to resist, to maintain the balance of keeping players because of their on-pitch performance, but at the same time we also need to maintain a structure and stability."