Pace bowler James Anderson has sustained a “mild strain to his right groin”, say the England and Wales Cricket Board (ECB).
Anderson, 40, left the field on day one of Lancashire’s match against Somerset on Thursday and took no further part as the game ended in a draw on Sunday.
The ECB said Anderson’s fitness will be assessed nearer the time of the Test against Ireland, starting on 1 June.
Anderson had a scan on the injury on Saturday.
England will name their squad for the match against Ireland at Lord’s this week. The five-Test Ashes series against Australia starts on 16 June.
Lancashire head coach Glen Chapple earlier told BBC Radio Lancashire that Anderson’s injury is not “anything too serious” and “we should be positive about his recovery”.
Anderson, England’s all-time leading wicket-taker, has been hit by injuries in each of the past two home Ashes series.
He bowled only four overs before suffering a calf problem in the first Test of the 2019 series, which was drawn 2-2.
In 2015, he suffered a side strain in the third Test as England went on to win 3-2.
Any long-term problem for Anderson would add to a growing injury list in England’s fast-bowling department.
Captain Ben Stokes has previously spoken of his desire to have eight fast bowlers available for each Ashes Test, but in recent weeks injuries have hit Jofra Archer, Olly Stone and Brydon Carse.
Archer returned home from the Indian Premier League with a recurrence of his long-term elbow problem, Stone suffered a hamstring injury playing for Nottinghamshire and the uncapped Carse has picked up a side injury playing for Durham.
In addition, Jamie Overton is only in the early stages of his comeback from a stress fracture of his back.
Still, of that quartet, only Overton has featured for England in their run of 10 wins out of 12 under captain Stokes and coach Brendon McCullum.
First-choice pair Ollie Robinson and Stuart Broad sat out the latest round of County Championship matches for Sussex and Nottinghamshire respectively, while Mark Wood is missing the latter stages of the IPL to be at the birth of his second child.
Back-up could come from the likes of Matthew Potts, who has been in fine form for Durham, and Saqib Mahmood after his recovery from a long-term back injury.
England could also call on the experience of Chris Woakes and Sam Curran, all-rounders who have good records in home Tests.
