Is it a matter of when, not if, Tyrone Mings receives an England Under-21 call-up and become the Championship’s best left-back.

So says Ipswich Town boss Mick McCarthy following the 21-year-old’s rapid development this season.

Signed from third tier non-league club Chippenham Town in December 2012, Mings had to patiently wait for his chance before Aaron Cresswell – voted the division’s best player in his position last season – was sold to West Ham for £3.75m in the summer.

Few saw the athletic 6ft 3in defender improving as quickly as he has done. Town rejected a £3.5m bid from Premier League club Crystal Palace on transfer deadline day, he was soon named the Championship Player of the Month for September and now has scouts from Arsenal, Chelsea and Everton monitoring his progress.

It therefore came as a surprise that he was overlooked for the latest England Under-21 squad last week, Everton’s inexperienced Luke Garbutt and Huddersfield Town loanee Jack Robinson (QPR) preferred.

“I can’t believe any of them in there are better than him, but maybe it’s not a bad thing that he hasn’t been called up,” said McCarthy. “I’d sooner him have a few days off. He’s just got in to our team this season, he’s got a new contract, he had Crystal Palace in his ear, everything’s been going for him – he’s progressing.

“Whoever is in that squad, good luck to them. Let Ty have a rest, because I think he’ll benefit from that. He’ll get in it. I don’t doubt that at all because if there are any that are any better than him in that squad I’d be interested to see them.

“But it suits me that he’s not in there though. That’s me being selfish. It’s his first full season and that’s demanding physically. Let him have the time off and leave the Under-21s to get on with it.”

Asked if he had potentially replaced the best left-back in the league with the new best left-back in the league, the Blues boss said: “Potentially. I think he (Mings) has to do it over a bit more than 17 games, to be honest.

“I haven’t seen them all yet. Until I do I can’t really judge. I’m yet to see a better one though and somebody is going to have to be very good to be better than him.”

He added: “I still see things that he has to improve on. He’s doing great, but there are things we pull him up on. He’s still learning and I think he’s still getting that stamina to play Saturday-Tuesday, Saturday-Tuesday.

“We will have the best left-back in the league eventually I think.”