Leeds: Chris Woakes said England's players faced a nervous wait as the countdown to the announcement of the World Cup squad entered its final phase.
Tournament hosts England unveil their squad for the one-day international showpiece on Tuesday.
England have yet to win a men's World Cup but they head into this year's edition as the number-one ranked side in ODI cricket.
Pace-bowling all-rounder Woakes settled what little doubt there was around his place with a five-wicket haul as England beat Pakistan by 54 runs at Headingley on Sunday to complete a 4-0 series win.
But David Willey, despite the variety he offers as a left-arm quick, has seen his place threatened by the emergence of newly-qualified Barbados-born fast bowler Jofra Archer.
And back-up spinner and reserve batsman Joe Denly could also be cut from the 17-man squad deployed against Pakistan when it comes to England's final 15 for the World Cup, especially with Liam Dawson waiting in the wings as an alternative slow-bowling option.
"Everyone will be looking at their phones," said Woakes following his Headingley haul of five for 54.
"Everyone will be wary of that phone call. Even if you feel like you've got a good chance to being in the squad until you hear it from selectors' mouths, it's not quite set in stone," he added.
"As a player, you're still probably a little bit on edge, particularly with this 16 and 17 players because everyone has performed at some point over the series.
"In the last couple of years, people have put in strong performances. It's a tricky decision for selectors and I'm glad I'm not having to make that decision, but it has to be done I suppose.
"It's certainly driven us forward in this series."
Meanwhile, England one-day captain Eoin Morgan, who made 76 in a total of 351 for nine on Sunday, insisted he had yet to be told who was in the World Cup squad by selection chief Ed Smith.
"No, I don't know the 15," said Morgan.
"Every one of these guys should be proud of what we've achieved so far, the continuous improvement of performances throughout makes the selection meeting extremely difficult," the Dubliner added.
"But every single member of the 17-man squad here will play some role (at the World Cup), due to the nature of injuries and illness and call-ups."
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Jofra Archer has been RR's standout bowler with 17 wickets from 12 matches in IPL 2020.
Buttler, who started as an opener in the tournament, has been batting down the order in recent games. Against CSK on Monday he was at his destructive best, while skipper Steve Smith held the other end.
Pakistan will also play three T20 internationals during the tour, which was earlier scheduled to be held in September/October this year but had to be deferred due to the rising COVID-19 cases in South Africa.