England's Ashes preparations were dealt a blow on Sunday as frontline spinner Jack Leach was ruled out of the series due to a lower back stress fracture.

The 31-year-old developed the injury as England wrapped up victory in a lone Test against Ireland on Saturday.

"A scan on Sunday in London has revealed a stress fracture, which will keep him out of the forthcoming Ashes Test series," the England and Wales Cricket Board said in a statement.

No replacement for the Somerset left-armer has been announced, but Leach's absence leaves a big gap to fill for the selectors for the showdown against Australia.

He was the only spinner named in the 16-man squad on Saturday for the first two Tests and England's depth in that area will now be tested.

England head coach Brendon McCullum and captain Ben Stokes could opt for an all-seam attack, with Joe Root providing a spin option.

But that could be a risky approach with doubts over how many overs Stokes will be fit to bowl due to a knee injury.

Leach impressed during the winter tours of Pakistan and New Zealand to improve his Test tally to 124 wickets in 35 matches.

But teenager Rehan Ahmed also shone on his Test debut in Pakistan, taking seven wickets in one match at an average of less than 20 runs.

Surrey all-rounder Will Jacks is also in contention after he started the first two Tests in Pakistan.

The first of the five-Test Ashes series gets underway on June 16 at Edgbaston.