Jacks, 25, has played in all three formats for England over the past 12 months and was a surprise omission from the ECB's list of 29 players to receive a contract offer.

"It was a bit of a difficult one," Jacks said on the eve of England's ODI opener against West Indies. "I didn't really find out at all. I knew everyone was hearing and I was waiting to hope that I would find out and then I didn't. I just ended up seeing it on Twitter like everyone else did and that was obviously disappointing. I was hoping to get one."

Jacks is in high demand on the T20 franchise circuit, with contracts to play in the SA20 in January and the IPL in March. As a result, the omission has been a double edged sword, with Jacks now able to pick and choose his winter commitments as he builds to his number one priority: making the squad for the 2024 World Cup.

"The last two World Cup years I've just narrowly missed out on selection, so making the World Cup squad is a massive goal of mine and playing T20 cricket in South Africa against some of the best players will be perfect for that."

The difficulty for England and Jacks, is that the SA20 clashes with England's Test series against India where, given the explosive batters' ability with the ball and his strong performances in Pakistan last year, he would be a likely candidate for selection in the squad, if not the playing XI.

"I wouldn't say it's changed my motivation to play for England," Jacks said in regards to whether the snub has led to him re-jigging his priorities. "Obviously England is the pinnacle and I want to play as much as I can, but what it has done is managed my expectations.

"The India Test matches have obviously been in the back of everyone's mind for the recent period - it's such a massive series and there's all the talk about spin and the need for allrounders and having a deep squad. So it's probably just that instead of me thinking that I was going to be picked I'm now thinking okay, if they wanted to pick me then realistically, I would have been given a contract. So the fact that they haven't given me one, probably says something."

"That [backing] is huge for everyone," Jacks said. "If you bring in a fear of failure or worry about if you are going to play or not, obviously that hinders your performance and you won't be able to go out there and play with 100 percent confidence. That is really important in any team you play for and especially for England. Everyone knows how high the competition is for places."

England are not expecting the three-match ODI series to be a high-scoring encounter, with the training wickets at the Sir Vivian Richards stadium taking a lot of spin and scores in and around the 250-300 mark assumed to be closer to par.

"It's going to be a bit more - not a grind - but you're really going to have to think your way through an innings and treat it like it is a longer formatthere's no worries of it becoming an extended T20."

Sunday's match kicks off at 9:30am, a non-issue for a group still just about on UK time and waking up at 6am naturally. But, on Saturday, the squad had an earlier wake up call than normal when an earthquake registering 5.2 on the Richter scale struck Antigua. No major damage on the island was experienced, but for a group of lads from Shires, Manchester and Surrey, it was a new experience.

"We're all claiming that we're earthquake survivors now," joked Jacks, who slept through the whole thing. "I woke up at about six, saw the messages on the group and couldn't really believe it. Some of the guys said their whole room was shaking and everything."

With England staying at a resort on the south-east corner of the island that looks straight out across the ocean, some players were more concerned than others.

"Brooky [Harry Brook] messaged me saying: 'Is there going to be a tsunami?' Jacks quipped at his mate's expense. "That was the first thing we thought but it's all good now."