London: England great James Anderson was forced to leave the field with a calf injury while bowling for Lancashire in their County Championship match against Durham yesterday.

With just a month until the Ashes start, any fitness concern surrounding the bowling spearhead of England’s Test attack, is sure to be a concern to the selectors ahead of a five-match series against arch-rivals Australia.

Anderson, 36, who took his 950th first-class wicket on Monday, stretched and attempted to run in three times to shake off the injury but was eventually forced to leave the field on the third day at Sedbergh School.