Dawson, the Hampshire spinner, played the last of his three one-day internationals in October and was not involved in the recent 4-0 series win over Pakistan.
Both Denly and Willey were named in last month’s provisional 15 but both men have seen their tournament dreams dashed.
Denly had been lined up as a utility option in the squad, a flexible batsman and a late-blooming leg-spinner, but England have used him sparingly as a bowler. Head coach Trevor Bayliss has admitted that Dawson’s slow left-arm spin is more reliable and a strong show in the Royal London Cup has pushed him over the line.
Willsey voiced his disappointment via his Twitter account where he said: “What can I say, I’m absolutely gutted. Still 100% behind the lads. On a positive.....still winning at life!!”
Left-arm seam bowler Willey, meanwhile, has paid for the emergence of the exciting Jofra Archer. The Barbados-born quick was yet to make his debut when the preliminary selection was made but swiftly became a must-pick after acing his early auditions on the international stage.
The third and final alteration from the initial squad became a necessity when Alex Hales was discarded following off-field indiscretions. James Vince was added in as his replacement ahead of the Pakistan series and holds his place.