Olly Morgan will make his England debut in their Six Nations opener against Scotland on Saturday after being called up to replace the injured Iain Balshaw.
Morgan was named in the Saxons side to take on Italy A on Friday
The 21-year-old comes in at full-back after his Gloucester team-mate failed to recover from a groin problem.
Balshaw suffered the injury during training on Wednesday and Morgan was called up from England Saxons duty as a precautionary measure.
Substitute flanker Lewis Moody was ruled out of the game on Thursday.
Moody, who has a shoulder problem, also picked up the injury in training and his place on the bench is taken by Wasps back-rower Tom Rees.
Morgan and Rees were originally named in the England Saxons side to face Italy A in Exeter on Friday but they both linked up with the senior squad at their Bath University base on Wednesday.
With Balshaw out, England coach Brian Ashton could have switched Josh Lewsey or Jason Robinson to the number 15 shirt and put Mathew Tait on the wing but has opted to go with the untried Gloucester back.
"I believe we need to pick the best players in their right positions," said Ashton.
"Mathew Tait has only played full-back once in his life, and I did not consider moving Lewsey or Robinson because they are best on the wing.
"Olly was very close to playing for England during the autumn before he was injured. He has all the qualities of an old-fashioned full-back, which he will find handy against Scotland.
I am delighted, this is something I have wanted to do since I was a kid
England full-back Olly Morgan
"He is good under the high ball, he is strong, and I am sure when the time is right he will come into the attack."
Morgan, who has represented England at under-21 and under-19 level, has made 38 appearances for Gloucester and scored eight tries since joining them during the summer of 2004.
"It will be the first XV-a-side match I have played at Twickenham. I get nervous before most games and I will be extremely nervous on Saturday," he told BBC Sport.
"I am gutted for Iain. He is an experienced player and one that I have looked up to from young but he has been really helpful.
"I just hope I can bring my Gloucester form onto this stage.
"I am delighted, this is something I have wanted to do since I was a kid. The fact I have this opportunity is really exciting."
606 DEBATE: Will Balshaw's absence affect England?
England will launch their campaign with a much-changed side, with only two players - flanker Joe Worsley and number eight Martin Corry - retained in their starting positions from the world champions' last match against South Africa in November.
Revised England team to face Scotland:
Morgan (Gloucester); Lewsey (Wasps), Tindall (Gloucester), Farrell (Saracens), Robinson (Sale); Wilkinson (Newcastle), Ellis (Leicester); Freshwater (Perpignan), Chuter (Leicester), Vickery (Wasps, capt), Deacon (Leicester), Grewcock (Bath), Worsley (Wasps), Lund (Sale Sharks), Corry (Leicester).
Replacements: Mears (Bath), White (Leicester), Palmer (Wasps), Rees (Wasps), Richards (Gloucester), Flood (Newcastle), Tait (Newcastle).