He missed Monday afternoon's training session in Cardiff and is considered unlikely to feature in Tuesday evening's match. It is not yet clear whether he will return in time to play in the final match of the series, at The Oval on Thursday night, but at this stage it appears that he will travel to the Caribbean for the T20 World Cup with the rest of the squad on Friday.

While the news is disruptive to England in the short term, Buttler's absence should ensure that he is with the team throughout their World Cup campaign, which begins next Tuesday (June 4) in Barbados against Scotland. He had previously confirmed he would be at the birth regardless, raising the prospect that he could miss a group-stage match.

"Hopefully, the baby comes at the right time where he doesn't miss too many games. For me, it's just whatever will happen, will happen. [Deputising] is not really difficult, to be honest with you, because we speak often, me and Jos. We talk about other things, the team, and all that. We're on the same page anyway."

There is also a case for Duckett to replace Buttler at the top of the order, which would give England's first-choice batting line-up the chance to bat in their likely roles for the World Cup. Jacks looked in fine touch on Saturday, hitting 37 off 23 balls from No. 3, but admitted on Monday that he is still "learning on the job" having opened for most of his T20 career.

"It's no lie that I'm new to batting at No. 3," he said. "The biggest thing I've found is just the uncertainty of not knowing when I'm going in: obviously if I'm opening, it's 0 for 0 every time, bowling first or second. I know exactly what's going to happen: I'm facing the swinging ball or, if it's a spinner opening, I know what the field is going to be.

"[Batting at No. 3] is just a different scenario each time, which is more of a mental thing. I know I've got the game and the technique. It's just adjusting to coming in outside the Powerplay, coming in the fifth over: when do I put my foot on the pedal? It's about figuring out what I need to do at the right time it's all about the team, not about yourself."

In any case, Tuesday night's match is under threat from the weather, though Jacks suggested that playing a shortened match could serve as useful preparation for the World Cup. "Preparation is not always ideal, but we have to be adaptable and T20 is all about thinking fast on your feet, and assessing the situation as quickly as possible," he said. "We'll be ready for anything."