MORE: Forgotten Finn rips apart flimsy Aussies
James Anderson's 33rd birthday was spoiled as he was forced from the field against Australia with a side strain.
Anderson had been superb in taking 6-47 on day one of the third Ashes Test at Edgbaston, and followed that up with the wicket of David Warner on Thursday.
But there was concern for the hosts as he had to pull out midway through an over in the evening session on day two.
With the fourth Test at Trent Bridge set to get under way in a week's time, England will be desperately hoping their all-time leading wicket-taker is fit to play.
Anderson, clearly in discomfort, attempted to stretch off the problem but pulled out halfway through his run-up, leaving the field looking dejected as Joe Root finished his over.
The ECB later confirmed Anderson had suffered "a tight side" and "will be assessed overnight and in the morning".