England World Cup winner Steve Thompson's hopes of a Test match recall against Scotland next week could be threatened by injury.
The Northampton hooker, capped 47 times, has not played for England since last season's RBS 6 Nations Championship, but he is thought to be in pole position to reclaim the number two shirt above rival candidates George Chuter and Lee Mears.
Thompson will miss Saints' Guinness Premiership appointment with leaders Bristol on Saturday because of a neck problem.
Northampton head coach Paul Grayson said: "Steve had some ongoing neck trouble which creates a loss of feeling in his arm, and he took a fairly heavy bang on it last week.
"He will have all the scans and the usual wonderful things the medical department offer, and maybe he will be available for England next week."
England head coach Brian Ashton has already ruled wings Paul Sackey and Mark Cueto out of his selection plans for the Calcutta Cup.
Wasps flier Sackey is battling to overcome a knee injury that also threatens to sideline him from Italy's Twickenham visit on February 10. Sale Sharks star Cueto is laid low by a calf muscle problem.
But brighter news has emerged about England's 2003 World Cup match-winner Jonny Wilkinson, who could return to action tomorrow after 12 weeks out recovering from a lacerated kidney.
Wilkinson looks set to launch his latest comeback - as a replacement - when Newcastle resume their Premiership campaign against Heineken Cup quarter-finalists Leicester at Welford Road.
Ashton said: "Recent history shows that when Jonny comes back from injury, he plays better than he was in the game before he got injured. It is almost unbelievable.
"He is a lot more mature now, and I think his understanding and knowledge of the game has developed during all of his time out injured.
"He brings a wealth of experience, and if you match that with his skill set, you have a world-class player on your hands.
"He has been staggering in training this week. I hope he will be back in the team as soon as possible."
Ashton has cut his squad for the Scotland game from 33 to 29 players, with Bristol scrum-half Shaun Perry and Gloucester lock Alex Brown both joining the England Saxons squad ahead of next Friday's fixture against Italy A in Exeter.
After missing out on England's 2015 RBS 6 Nations campaign through injury, centre Brad Barritt admits he is determined to make up for that disappointment in style with club side Saracens during the season run-in.