Jose Mourinho intends to operate at Manchester United with a core first-team group of just 24 players and will allow anyone outside that to leave the club or train with the under 21s.

Mourinho, who used 22 players when he clinched the Premier League title at Chelsea two seasons ago, will stick to the same principle at Old Trafford that a small, tight-knit group is preferable to a bloated squad with players frustrated at a lack of game-time.

The new United manager has already made his strategy clear to the players who were not at Euro 2016 and have returned to pre-season training.

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Juan Mata (left) and Marouane Fellaini (centre) face a fight to stay at Manchester United

At a meeting Mounrinho explained he planned to have 24 players as his first-teamers and everyone else would have to decide if they wanted to leave, either permanently or on loan, or stay and train with the under 21s.

MOURINHO'S CHOSEN 24? Goalkeepers: De Gea, Romero, Johnstone. Defenders: Jones, Valencia, Darmian, Shaw, Smalling, Fosu-Mensah, Borthwick-Jackson, Bailly. Midfield: Mkhitaryan, Pogba, Herrera, Depay, Carrick, Schneiderlin,Young, Lingard, Pereira Forwards: Ibrahimovic, Rooney, Rashford, Martial Advertisement

The Red Devils used 33 players in the Premier League under Louis van Gaal last season and even allowing for injuries, Mourinho believes that is far too many to encourage organisation and team spirit.

Premier League clubs are allowed to name a 25-man squads plus under 21s players but Mourinho doesn't want that many even though United will also have a Europa League campaign to cope with.

The atmosphere at United's training ground in Mourinho's first week has been described as business-like with less chit-chat off the training pitch with the Portuguese manager even compared to Van Gaal.

Jose Mourinho intends to operate at Manchester United with a core first-team group of just 24 players

The first casualties of his tunnel vision approach appear to be young defenders Guillermo Varela and Tyler Blackett, who have already been sent to train with the reserves despite United's first-team squad currently being short of numbers until Wayne Rooney, Chris Smalling, Anthony Martial, Maroune Fellaini, Marcus Rashford, Matteo Darmian, Morgan Schneiderlin return from post-European Championship holidays, or wedding in the case of Bastian Schweinsteiger.

Uruguayan Varela, 23, was David Moyes' first signing and made 11 first-team appearances for United, while centre-half Blackett has played a dozen times and spent last season on loan at Celtic.

Another loanee James Wilson is in the first-team group for now following his return from Brighton and could feature in Mourinho's first pre-season friendly at Wigan on Saturday.

Daley Blind could find himself surplus to requirements despite impressing in an injury-hit team last season

Striker James Wilson will be given the chance to stake a claim after spending last season on loan at Brighton

Big-name internationals including Juan Mata, Daley Blind and Marcos Rojo are also in danger of missing the cut with Mourinho having already signed Eric Bailly, Zlatan Ibrahimovic, Henrik Mkhitaryan, and also in the chase for Juventus and France star Paul Pogba.

Michael Carrick, Mata, Phil Jones, Jesse Lingard and Ashley Young are among first-teamers who will be available for Wigan.