Yorkshire's Jonny Bairstow expected to replace Jason Roy for Champions Trophy semi-final

Captain Eoin Morgan declined to confirm the switch, citing tournament protocol to resist divulging his team before the toss. It was inconceivable, however, on the evidence of England’s morning net session that the out-of-form Roy would remain in situ after his run of low scores caught up with him - and Bairstow will therefore have a belated chance to join the hosts’ bid for a first 50-over global trophy in their history.

England’s Test wicketkeeper was among the first to bat, while Roy was left to throw in the big hits from the outfield and had time in between for a long chat with coach Trevor Bayliss just in front of the boundary hoardings.

Morgan was previously adamant on several occasions, since England began their campaign just under two weeks ago, that Roy would stay in position for the duration alongside Alex Hales at the top of the order come what may.

After the Surrey batsman’s miserable form extended to 51 runs in eight innings with his latest failure in the weekend win over Australia at Edgbaston, it appears the captain has changed his mind - even if he declined to confirm it at his pre-match press conference.

Morgan came closest to doing so when he said: “There’s a chance we could make a change.”

Many of his subsequent answers provided significant indication that it will be Bairstow who is asked to face the new ball against Pakistan left-armers Mohammad Amir and Junaid Khan.

“Obviously, we won’t announce the team until the toss,” he added. “I mentioned after the last game that we’re getting to the business end of the tournament and we need to produce results.

“So it’s important that tomorrow we pick what we feel is our best XI to win the tournament.”

Bairstow will be thrust into the team at a venue where he first burst onto the international scene with a match-winning debut against India in 2011.

In more recent times, he has earned a reputation as England’s white-ball supersub - rarely in their first-choice team but never letting them down when needed.

“I believe Jonny’s a fantastic batsman,” added Morgan. “I think his best attribute, certainly in white-ball cricket over the last year-and-a-half, has been his relentless attitude to score runs - regardless of the situation. “When you have guys sitting on the sideline, they can get a little bit upset, and that can affect their performance when the actual chance comes along - but that doesn’t seem to affect Jonny.

“Every time he gets a chance, he’s been in a great frame of mind.”

Bairstow proved that especially when he was called into a series decider against New Zealand at Chester-le-Street two years ago, after Jos Buttler was injured, and responded with another man-of-the-match performance by making 83 not out in a successful run chase.

“That sums him up,” said Morgan. “He came from playing in Yorkshire to coming straight into the squad, having played no part in the series, and came in and produced a match-winning knock.

“I think his all-around ability is as good as we have in this squad. But as I’ve mentioned before, it’s a very difficult team to get into, and you’ve just got to wait for that chance.”

Bairstow has no international pedigree, however, as an opener.

Even so, following his List A career-best for Yorkshire at the top of the order last month, Morgan said: “I’d have no worries if he has to open the batting ... if Jonny does get the opportunity, I’m sure he’ll take it with both hands.”

Mentioning no names, he added: “I back all my players. I see the best in them, and I believe in them a huge amount. Getting to this stage of the tournament, we need results - and if that means somebody misses out, it’s unfortunate.

“But for the team’s sake, we need to get results. We want to win this tournament.”