Injured Anderson racing clock for first Ashes Test

James Anderson has been ruled out of England's four-day Test against Ireland at Lord's starting on Wednesday but World Cup star Jason Roy will make his debut.

Opening bowler Anderson has failed to recover from the right calf injury he sustained when playing for his county Lancashire against Durham on July 2.

"Jimmy will continue to be assessed" ahead of the first Ashes Test at Edgbaston on August 1, an England and Wales Cricket Board statement said on Tuesday.

Chief selector Ed Smith stated when naming the squad last week that England's record wicket-taker would not be risked ahead of the Ashes series if there were any lingering doubts over his injury.

Bowling resources have already been stretched by side strains sustained by Mark Wood and Jofra Archer in the recent World Cup victory over New Zealand.

Warwickshire paceman Olly Stone will make his Test debut in Anderson's absence, with World Cup-winning batsman Roy also playing his first Test after featuring in 84 one-day internationals.

England will play two spinners in Jack Leach and Moeen Ali in an attack led by Stuart Broad, with uncapped all-rounder Lewis Gregory missing out from the original 13-man squad.

Test skipper Root, speaking at Lord's on Tuesday, said Anderson could have played against Ireland but stressed that England did not want to take any chances with their prize asset ahead of a five-Test Ashes series.

"Jimmy probably would have been able to get through this Test match but (it's) just making sure that he's absolutely ready," Root explained.

"We thought the last thing we want is him carrying a niggle going into a series so we tried to be sensible about it and give him as much time to be 100 percent going into that series – a five-match series. So we're very confident that he'll be fit (for the Ashes)."

The powerful Roy will open the innings, as he did during the World Cup, even though he is a middle-order batsman in first-class cricket.

"With Jason, we want him to be himself, express himself and trust his instincts as much as possible," Root said.

"He brings something different to our Test batting side, he's a proven performer in international cricket and fully capable of making big contributions. I hope he doesn't try to play differently, I hope he'll go and be himself.

"There were occasions in the World Cup when he had to trust his defence and he might have to draw that out a bit longer in Test cricket – but he can go and put the pressure back on the opposition. He's one of the best in the world at that."

Anderson, 36, no longer plays ODI cricket so did not play in the World Cup.

The Lancashire swing bowler, with 575 scalps, trails only the spin trio of Sri Lanka's Muttiah Muralidaran (800 wickets), Australia's Shane Warne (708) and India's Anil Kumble (619) in the all-time list of Test wicket-takers.

England XI: Jason Roy, Rory Burns, Joe Denly, Joe Root (c), Jonny Bairstow (wk), Moeen Ali, Sam Curran, Chris Woakes, Stuart Broad, Olly Stone, Jack Leach.

2019 Qantas Ashes Tour of England

Tour match: Hick XII v Haddin XII, July 23-26

First Test: Edgbaston, August 1-5

Tour match: Australians v Worcestershire, August 7-9

Second Test: Lord's, August 14-18

Third Test: Headingley, August 22-26

Tour match: Australians v Derbyshire, August 29-31

Fourth Test: Old Trafford, September 4-8

Fifth Test: The Oval, September 12-16