England seam bowler James Anderson remains a doubt for the fourth Test against India at the Oval as he struggles with a minor thigh injury.The 29-year-old experienced tightness in his right quadriceps following the third Test at Edgbaston and only played a limited part in Tuesday's practice.England will definitely be without bowler Chris Tremlett, who failed a fitness test on his injured back.
Graham Onions will provide cover for the Test which starts on Thursday.
Anderson appeared to show little discomfort from his thigh injury during fielding drills on Tuesday but he did not bowl in the afternoon.
England team-mate Graeme Swann, however, remains hopeful Anderson will be fit in time for Thursday.
"I honestly didn't know he was injured until this morning when he told me everyone was saying he's not going to play," said Swann.
"Jimmy seemed fine to me - I'm sure it's just a bit of stiffness.
"I know how well he's bowling at the minute - and when he's doing well he's hungry for the ball and just wants to keep going."
Should Anderson, who has been in superb form during the ongoing series with India, taking 18 wickets at 24.27, not make it along with Tremlett, Swann concedes it would be a blow to England.
However, the 32-year-old is confident England's bowling line-up is strong enough to cope with the absentees.
"He would be a huge loss, like any of the seamers," he added. "But we have got vast stocks of fast bowlers at the minute."
Tremlett played in the first Test at Lords, which England won by 196 runs, taking four wickets, but a back injury saw him miss the second Test at Trent Bridge and the following match at Edgbaston, with Tim Bresnan excelling in his place.
National Selector Geoff Miller, said: "Unfortunately Chris Tremlett has failed a fitness test and won't be available for selection for the fourth Test, despite showing strong signs of recovery over the past few days.
"Chris' absence in conjunction with what appears to be a minor injury concern with Jimmy Anderson has led to a call up for Graham Onions as precautionary bowling cover.
"We are hopeful that Jimmy will overcome this niggle by Thursday but more time is required before a decision on his availability can be made conclusively."
Onions' call-up to the Test side is his first since leaving the tour of Bangladesh in March 2010 with a back injury that meant he missed the whole of the season that year.
England squad for Oval Test starting on 18 August: Andrew Strauss (Middlesex, captain), James Anderson (Lancashire), Ian Bell (Warwickshire), Ravi Bopara (Essex), Tim Bresnan (Yorkshire), Stuart Broad (Nottinghamshire), Alastair Cook (Essex), Steven Finn (Middlesex), Eoin Morgan (Middlesex), Kevin Pietersen (Surrey), Matt Prior (Sussex, wk), Graeme Swann (Nottinghamshire), Graham Onions (Durham).
