Durham quick Steve Harmison is likely to miss a minimum of two more matches as he continues his recovery from a back injury.
The 31-year-old, who has been ruled out for the start of the domestic season, is suffering from a trapped nerve in his back and is not expected to return before next month.
Harmison, who has 63 England Test caps to his name, will therefore be absent for Durham's opening Clydesdale Bank 40 match against Hampshire on Sunday, as well as their LV= County Championship match at Yorkshire next week.
After taking 51 wickets in Durham's championship-winning season last year, Harmison is yet to play this term, missing the two opening matches of his side's title defence.
Durham clinched a home draw with Essex in their opening match while their ongoing clash with Hampshire could reach the same result.
England seamer Graham Onions will also have his fitness assessed by Durham's medical team on Monday.
Onions made an early departure from England's tour of Bangladesh due to a back injury and his comeback was delayed last week when he complained of a similar pain during a training session at the Riverside nets.
Durham suffered a further blow to their fast-bowling stocks when Mitch Claydon suffered an abdominal muscle strain against Hampshire on Friday and is not expected to bowl again in the match.