London, July 7 (IANS) England's all-time leading wicket-taker James Anderson tore a calf muscle during Lancashire's County Championship match against Durham, thus making him doubtful for the upcoming Ashes starting next month.

Anderson (36) suffered "a low grade calf muscle tear" on Day 3 of the match at Sedbergh on Tuesday, according to a BBC report.

With 575 wickets in 145 Tests, Anderson is the most successful fast bowler in the history of Test cricket.

The first of the five Ashes Tests between England and Australia starts on August 1 at the Edgbaston.

--IANS dm/arm