Jonny Wilkinson underwent a scan yesterday after turning up for England duty ahead of the forthcoming autumn international campaign nursing a shoulder problem.
The Toulon fly-half is one of five England players struggling with injuries less than a fortnight before Martin Johnson's men tackle New Zealand at Twickenham on 6 November.
Wasps pair Riki Flutey and Simon Shaw both have calf problems, flanker Hendre Fourie damaged ribs in Leeds' 6-3 defeat to Sale on Friday night and the Bath tighthead David Wilson has a back injury.
Sale fly-half Charlie Hodgson was called in as cover for Wilkinson while rookie Harlequins prop Joe Marler joined the England squad to deputise for Wilson. Northampton flanker Tom Wood, Saracens centre Brad Barritt and Wasps' versatile forward Dan Ward-Smith also joined the England squad yesterday.
Wilkinson started the season in prime form for Toulon and is pushing for a return to the England starting XV after losing his place to Toby Flood during last season's Six Nations.