There have been widespread calls for Brook’s inclusion ever since he was surprisingly left out of a provisional 15-man named squad last month and his late addition in place of opener Roy is the only change to that group.
Roy played a key part in England’s 2019 World Cup success on home soil but has endured prolonged periods of poor form over the past two years and, crucially, missed all four matches of this month’s series against New Zealand with back spasms.
In the 33-year-old’s absence, Dawid Malan excelled at the top of the order, scoring 277 runs in three innings including a century in Friday’s Fourth ODI at Lord’s.
He now looks nailed on to open the batting alongside Jonny Bairstow in India, meaning Roy’s role would have been as the squad’s spare batter and given concerns over the Surrey man’s fitness, as well as his lack of versatility to bat lower down the order, England have deemed Brook a better fit for that spot.
“The strength of the group has meant we have had to make some tough decisions on world-class players,” said national selector Luke Wright.
Nonetheless, the news will come as a bitter blow to Roy, who scored ODI hundreds in his two most recent series - away to South Africa and Bangladesh at the start of the year - and was also dropped on the eve of last year’s T20 World Cup triumph.
Brook already has a World Cup winners’ medal to his name from that tournament and has endured a remarkable start to life as a Test cricketer, averaging 62 at a strike rate above 90 so far in his short career.
Commitments in other formats have several limited the 24-year-old’s opportunities in ODI cricket thus far and his record is unremarkable, with an innings of 80 on the tour of South Africa his only score above 25 in six knocks.
However, two of those came as a makeshift opener in the recent New Zealand series and Brook’s form this summer has otherwise been excellent, the Yorkshire batter enjoying an increasingly impressive debut Ashes and then striking the Hundred’s fastest century just days after being left out of the provisional World Cup squad.
Brook had been named in a second-string squad to face Ireland in a three-match series starting on Wednesday but will now sit out those games to rest ahead of England’s departure for the subcontinent.
England are yet to name their three travelling reserves for the tournament, who could come into the squad in case of injury, but are expected to do so on Monday.
Brydon Carse, who like Brook played in the recent New Zealand series despite not being in the World Cup squad, could be included as one of those, as could Jofra Archer, who returned to light training with the team this week as he builds his way back from a stress fracture of the elbow.
England’s World Cup squad:
Jos Buttler (Lancashire – captain)
Moeen Ali (Warwickshire)
Gus Atkinson (Surrey)
Jonny Bairstow (Yorkshire)
Harry Brook (Yorkshire)
Sam Curran (Surrey)
Liam Livingstone (Lancashire)
Dawid Malan (Yorkshire)
Adil Rashid (Yorkshire)
Joe Root (Yorkshire)
Ben Stokes (Durham)
Reece Topley (Surrey)
David Willey (Northamptonshire)
Mark Wood (Durham)
Chris Woakes (Warwickshire)