Alex Hales has been withdrawn from all England squads ahead of the international season in the wake of his 21-day ban for using recreational drugs.
According to an ECB statement, Ashley Giles, ECB's managing director of England men's cricket, and the England selectors, headed by Ed Smith, took the decision after considering what is in the best interests of the England team.
"Consideration was given to creating the right environment within the team and ensuring that there are no unnecessary distractions and that the team is in the best position to succeed going into this crucial period," read the statement.
Hales will not travel to Ireland for a one-off ODI on Friday in Malahide and has also been removed from England's squad for the T20I, the one-day series against Pakistan, and the preliminary World Cup squad.
"We have thought long and hard about this decision," Giles said. "We have worked hard to create the right environment around the England team and need to consider what is in the best interests of the team, to ensure they are free from any distractions and able to focus on being successful on the pitch.
"I want to make it clear this is not the end of Alex's career as an England player. The ECB and the PCA will continue to aid Alex and work alongside his county club Nottinghamshire to give him the support he needs, to help him fulfil his potential as a professional cricketer."
England will name a replacement for the ODI series against Pakistan in due course.
Last week, it was announced that Hales had failed a drugs test, having tested positive for a recreational drug in recent weeks.
He is currently serving a 21-day ban after returning a second positive test, having pulled out of Nottinghamshire's Royal London Cup campaign, shortly after the World Cup squad was announced, for undisclosed personal reasons.
The drugs violation is understood to have been detected after Hales underwent a routine hair-follicle test, which all professional men's cricketers and centrally contracted women's players undergo at the start and finish of every season.
This incident is just the latest disciplinary issue to have affected Hales' career. In December, he was handed a six-match ban - four of which are still suspended - and fined by the ECB following the Cricket Disciplinary Commission's inquiry into the fracas outside Mbargo nightclub in September 2017 that led to Ben Stokes' arrest and subsequent trial for affray.
Hales has not been a first-choice player in England's white-ball squad since being dropped in the wake of that incident, with Jonny Bairstow and Jason Roy forging a successful partnership at the top of the order.
However, in June last year, Hales' 147 from 92 balls was the key innings in England's world-record total of 481 for 6 against Australia at Trent Bridge, and the strength that he would have added to England's squad depth will be keenly missed, especially now that his most obvious understudy, Sam Billings, has been ruled out of the season due to a dislocated shoulder.
England have until May 23 to finalise their World Cup 15, and so the coming series against Ireland and the Pakistan matches represent a huge opportunity for a replacement batsman to make his case for selection. The current front-runner would appear to be Hampshire's James Vince, who made a career-best 190 from 154 balls against Gloucestershire last week.