Manchester United transfer news: 'Serious' Kobbie Mainoo twist amid 'deadline' rumours ahead of January

Napoli's hopes of signing Kobbie Mainoo from Manchester United have taken a hit after a self-imposed deadline passed, the latest report has claimed.

United suffered a 2-1 defeat away to Aston Villa on Sunday, and the loss left them three points adrfit of the top four in the Premier League.

Boss Ruben Amorim will be concerned that midfielder Bruno Fernandes was forced off due to a muscle injury, and his absence from the first team compounds the team's issues ahead of January.

Youngster Mainoo is also dealing with an injury but has repeatedly been linked with an exit, and his possible departure would leave the club's midfield ranks threadbare.

Transfer expert Luca Marchetti has reported that Napoli have found it difficult to negotiate a reasonable price with United, and with hopes of having a deal in place by Christmas now over, the Italian giants are said to be resigned to missing out on the Englishman in January.

Kobbie Mainoo future: Why Ruben Amorim needs youngster

Fernandes has been key to much of United's success this season, but he is expected to miss at least a month of action due to a soft tissue injury.

The 31-year-old has started ever Premier League game this season, and Mainoo's injury means that Casemiro and Manuel Ugarte are now the Red Devils' only available senior midfielders,

Though Mainoo is likely to be on the treatment table for a few weeks, selling him in the winter would place even more burden on Fernandes to stay fit for the rest of the campaign, especially considering Ugarte and Casemiro have struggled to find form this term.

Signing a midfielder such as Brighton & Hove Albion's Carlos Baleba in January may help to facilitate Mainoo's exit, but it remains to be seen if United can match the Seagulls' asking price.

Could Lisandro Martinez be a solution for Manchester United?

When Fernandes was substituted off last Sunday, centre-back Lisandro Martinez was brought on in midfield, and he performed admirably despite the fact he ended on the losing side.

The Argentine is arguably the club's most progressive passer in defence, and his ability on the ball could be useful in the middle of the pitch, especially if Mainoo was sold and Fernandes struggles to recover from injury.

Whether the defender could adapt to a role in midfield is not yet clear, but his tenacity out of possession could improve the club's performances out of possession.

Amorim could alternatively look to utilise other youth prospects, with Jack Fletcher having made his senior debut against Villa, though relying on the 18-year-old would be risky given his lack of experience.