Birmingham, Aug 1: James Anderson will have a scan on his calf after bowling just four overs in the first session of the Ashes.
The England seamer conceded a solitary run from a probing new-ball spell at Edgbaston, as the hosts reduced Australia to 83-3 at lunch.
However, the availability of England's all-time leading wicket-taker for the rest of the match is in question after the ECB confirmed he is suffering from tightness in his right calf.
Anderson injured the same muscle on July 2, while playing for Lancashire against Durham, with the problem keeping him out of action until this week.
Stuart Broad took 2-17 and Chris Woakes 1-17 in a strong start for England, although the decision to pick Anderson ahead of Sam Curran, Olly Stone and Jofra Archer – the seam trio omitted from the hosts' 14-man squad - is likely to be called into question if he is unable to return.