The Bath forward suffered a sprained right shoulder during his club's Guinness Premiership defeat against London Irish two days ago.

Stevens, who started both of England's opening RBS 6 Nations Championship games against Wales and Italy, underwent an MRI scan on Sunday and then saw a specialist.

If, as looks likely, Stevens is ruled out of Saturday's appointment with Scotland in Edinburgh, then Leicester tight-head Julian White would be favourite to replace him.

We will be monitoring the situation with Matt overnight, said England head coach Andy Robinson, who is due to announce his starting line-up on Tuesday.

While Stevens continues his fitness fight, Robinson is optimistic that Wasps backs Tom Voyce and Josh Lewsey will both be available for selection.

Voyce, who started at full-back instead of shoulder injury victim Lewsey against Italy in Rome nine days ago, lost teeth during Wasps' 9-9 Premiership draw with Bristol.

Tom has had dental treatment for the teeth he lost in the Bristol game, and our medical team believes he will be fit and available for selection, added Robinson.

It is good to see Josh back with the squad, and he also looks as if he is in contention for selection as well.

If both players are fit, then Lewsey would be favourite to return in the No 15 shirt, with Voyce dropping to the bench.

Elsewhere, Robinson has called up uncapped Northampton centre Jon Clarke to his squad instead of Wasps' Stuart Abbott.

Abbott limped off after just 11 minutes at Bristol suffering from severe bruising to his right lower leg, and he will remain with his club this week for treatment.

Clarke, one of the form centres in English rugby this season, performed well for England A when they defeated their Italian counterparts two weeks ago.