Manchester United are ready to play hardball over the future of Alejandro Garnacho with Napoli and Chelsea seeking reassurances about the winger’s temperament.

Napoli have held a firm interest in Garnacho, while the Argentina international is one of a number of forward players Chelsea have made a check on this month.

But both clubs have doubts about committing as much as £50 million to trying to buy Garnacho in the January transfer window amid questions surrounding his temperament.

Bruno Fernandes, the United captain, has questioned Garnacho’s attitude in the past and this season claimed the 20-year-old did not celebrate a goal against Leicester City because he felt he had lost the faith of supporters.

Garnacho was dropped for the Manchester derby last month by head coach Ruben Amorim and there were reports of dissent towards the manager at the Europa League game against Viktoria Plzen.

It is understood that Napoli and Chelsea have attempted to get reassurances over Garnacho’s attitude as part of their homework on him.

United are not currently in talks with clubs about the sale of Garnacho and are not actively attempting to create a market for the player, which was underlined by the fact he started in Thursday night’s victory over Southampton.

Furthermore, it is understood that United are adamant Garnacho will not be allowed to leave Old Trafford in a cut-price deal this month. The club are similarly insistent that they will not take players they do not really want as part of any trades.

Napoli have banked around £60 million from the sale of Khvicha Kvaratskhelia, but are understood to have a list of potential alternatives to Garnacho that includes Borussia Dortmund’s Karim Adeyemi and Bayern Munich’s Mathys Tel.

Along with Garnacho and Jamie Gittens, also of Dortmund, Tel is on the list of forward players Chelsea have made checks on this month. Adeyemi is also a player the club could look at a late January loan deal for if nothing else comes off.

Chelsea have recalled defender Trevoh Chalobah from his loan at Crystal Palace to help cover defensive injuries and are willing to consider the sale of a host of players to help fund a January signing.

Christopher Nkunku, whom Chelsea value at around £65 million, could net the club a considerable fee if Bayern Munich can strike a deal for him. It may require allowing Tel to go in the opposite direction in a separate deal.

Dortmund are interested in Carney Chukwuemeka, Renato Veiga and Kiernan Dewsbury-Hall, and it remains to be seen whether that could be significant to the futures of Gittens or Adeyemi.

AC Milan have been credited with an interest in João Félix and Chelsea head coach Enzo Maresca joked that, with so much noise surrounding so many of his players, January has been a “disaster”.

Chelsea have not won any of their past five Premier League games ahead of Monday night’s visit of Wolverhampton Wanderers. Asked how he is finding January, Maresca laughed and replied: “A disaster.” He added: “Off the pitch, it is a disaster because of so many noises that don’t help us, but I don’t think they help any club.

“It’s not just for us, it’s for every club and every manager. In this moment, whenever there is any noise about any player, it is not easy. You think the player can be focused on us, but in the end he is a human being. So if there is any noise about another club then he is probably not focused 100 per cent. But we need to adapt because it is like this.”