Sam Allardyce has claimed he has decided to leave Marcus Rashford out of his first 23-man England squad for the upcoming 2018 FIFA World Cup qualifier against Slovakia – following the Manchester United starlet has seen his starting appearances restricted following the summer arrival of Zlatan Ibrahimovic to Old Trafford. Meanwhile, the new boss has also hailed his "difficult" decision to overlook Ross Barkley, but added the Everton starlet still has the door open ahead of the future.

Rashford proved his worth once again on Saturday after coming off the United bench to score a dramatic injury-time winner in the Red Devils 1-0 victory at Hull City. Yet, only a day later, he was moved down to the Under-21 side following his participation in Euro 2016 under Roy Hodgson.

"Having international experience in the Under-21 side will be invaluable for us down the line. And I think if he's breaking into Manchester United's team he'll be in my squad," Allardyce explained in a press conference as quoted by Sky Sports.

"Having a full game with Gareth will be invaluable to us down the line. He's only a young man, let's not put too much pressure on him. Hopefully he scores goals for the U21s and gives me a decision to make next time."

Barkley's omission from Allardyce first squad is one of the biggest shocks despite the Everton midfielder being selected but not used by Hodgson at the Euro 2016.

Asked about his decision, the manager added: "It's been a well thought-out squad. We've had to make some very difficult decisions, none more so than Ross Barkley. For him its disappointing but the door is always open and I have to make these decisions. I feel the squad I've picked is the right one at this moment."

Meanwhile, Allardyce has also backed his decision to give a first call-up to Michael Antonio after comparing his breakthrough at West Ham with Jamie Vardy's impressive last campaign at Leicester City.

"The quality of the player that has shone through in every league he's played in, and the impact, his attacking flair, and scoring record form a wide position – that's what has made me pick him," the boss said. "I think it deserves to be in this squad, for me to have a look at him going forward. It's similar to Jamie Vardy. It shows how much it means if you've got guts and desire."

Allardyce also confirmed that he will announce the new captain on Tuesday (30 August) while failing to address whether Wayne Rooney will return to the attack, after Hodgson played him in the midfield at the Euro 2016.

"It's not a reflection of where I'm likely to play him," the boss said. "Shall we say attacking-midfielder? Or striker? I think Rooney's position has changed at Manchester United and that's where I'll be looking to play him. I may consider changing the format of the squad announcement next time, so it says no position!"