Both players were key to Sunday's victory over France at Twickenham
England are awaiting fitness updates on Toby Flood and Joe Worsley, who were both injured in Sunday's crushing 34-10 Six Nations defeat of France.
Manager Martin Johnson is due to announce his team for Saturday's match against Scotland on Wednesday morning.
Fly-half Flood suffered a shoulder injury against France, while flanker Worsley suffered a gashed right thumb.
Wasps flanker Tom Rees could be in for a surprise recall if his Wasps team-mate Worsley fails to recover in time.
Rees has only had two full appearances since returning from a knee injury but the England management are confident he is ready for a Test match return if Worsley is sidelined.
Hopefully, it is not too bad. If it needs an injection, it needs an injection
England fly-half Toby Flood
Forwards coach John Wells said: "Tom is a quality international player. We are confident of his current fitness and I don't think we would have pressed him into action if we didn't have confidence in his ability to perform at this level."
However, Worsley would be a big loss for England after he scored one of the four tries in an incredible first half display against France.
If he can prove his fitness, Flood will be hoping to retain his starting place after scoring three conversions and a penalty in Sunday's emphatic display.
The Leicester number 10 suffered a similar injury in last summer's England tour to New Zealand.
"Hopefully, it is not too bad. If it needs an injection, it needs an injection," said Flood, who will be replaced by Andy Goode in the starting XV if he is unable to prove his fitness.
Meanwhile, Gloucester's Olly Barkley has been promoted above both Danny Cipriani and Shane Geraghty to be placed on standby to join the Test squad in case Flood fails to recover.
Barkley was dropped from the elite squad in January and his elevation confirms Cipriani and Geraghty have slipped further down England's pecking order.
Northampton's Ben Foden and Wasps prop Tim Payne have also joined the England squad for training this week.
The victory against France has sparked renewed optimism in the England camp and they could yet secure second place if they beat Scotland and Grand Slam-chasing Ireland defeat Wales in Cardiff.