Mahmood bowled 12 overs against Sussex but needs surgery

It means he will be unavailable for the remaining two Tests against the West Indies and the one-day series, which he would probably have been part of.

Mahmood bowled 12 overs as Lancashire drew with Sussex at Hove on Saturday but will have surgery on Tuesday.

He appeared in six of nine World Cup matches, taking eight wickets, but has not played in the current Test series.

"He has been having some discomfort since returning from the World Cup," said Lancashire cricket manager Mike Watkinson.

Our medical staff decided we needed to find out the cause (of the discomfort) Mike Watkinson

"Our medical staff decided we needed to find out the cause, and he will be having the operation next week."

Mahmood has not been hampered as a bowler, but has been struggling to a degree in the field, according to Watkinson.

"England are aware of the situation," he confirmed. "It will take five to six weeks before we can expect to have him back on a cricket field."

It means England's pace-bowling resources are further depleted, with Andrew Flintoff, Matthew Hoggard and Stuart Broad already on the sidelines.