Carrick arrives at training ground with future unclear

Michael Carrick arrived at Manchester United's training ground on Tuesday morning as doubts persist over the head coach's future at Old Trafford.

The 45-year-old's position is under major threat following United's poor start to the season, with work towards identifying his successor believed to be ongoing.

But no decision over Carrick's future had been communicated by Tuesday morning, with the Englishman arriving before first-team training at about 10:00 GMT.

It remains to be seen whether Carrick will take training, with United preparing to take on Chelsea at Stamford Bridge on Saturday (12:30 GMT).

Director of football Jason Wilcox, who has been criticised by supporters over the club's transfer business in the summer, was also pictured arriving at Carrington.

It is understood Eddie Howe and Julian Nagelsmann both feature prominently on the list of candidates the club has explored to potentially replace Carrick, and that both managers are aware of United's interest.

Sources have also indicated Aston Villa boss Unai Emery is admired at United, but the fact he is under contract would complicate any move for the Spaniard.

Multiple sources have told BBC Sport that former Newcastle boss Howe is fully open to joining United if Carrick loses his job.

Sources have told BBC Sport that Newcastle would be owed a multi-million pound compensation package should Howe join Manchester United - or any other club - following his resignation from the Magpies in the summer.

Howe stepped down in July following five years at Newcastle. He had three years to run on his deal.

Nagelsmann is available after leaving his job as Germany head coach after the World Cup, while Antonio Conte - who has also been linked with Juventus - is open to returning to football after leaving Napoli in May.

Carrick signed a two-year deal with United at the end of last season, after guiding the club to a third-place finish in the Premier League during an interim spell in charge.

Should he be dismissed, the 20-time English top-flight champions will be looking to appoint their eighth permanent manager or head coach since Sir Alex Ferguson departed the club in 2013 on the back of winning their most recent title.

Here, BBC Sport takes a closer look at the contenders who could be up for the job.