England [Images] fast bowler James Anderson is a major doubt for the forthcoming Test series against Sri Lanka [Images] after a suspected stress fracture was discovered in his back, the England and Wales Cricket Board (ECB) said on Monday.

Anderson has not featured for his county Lancashire since returning from England's recent tour of India.

"This is a huge blow for a player who has worked very hard to get back into the one-day international and test match environment," Lancashire coach Mike Watkinson said on the ECB's Web site.

England suffered another blow on Monday when fast bowler Simon Jones left the field with knee trouble during Glamorgan's C&G Trophy match against Ireland.

Jones, who missed England's tours of India and Pakistan with ankle and knee problems, will have a scan on Tuesday.

"We are liaising with the England medical team and will assess the position further after Simon has had a night's rest," Glamorgan physio Chris Towers said on Monday.

England captain Michael Vaughan [Images] (knee), fast bowler Steve Harmison (shin) and spinner Ashley Giles (hernia) are all ruled out of the first Test which starts at Lord's on May 11.