The camp will see some of England’s best young goalkeepers meet in January for training with specialist coaches Martin Thomas and Simon Smith.
A total of 18 keepers will work in two separate regional camps between 13 and 17 January, with players eligible for England U16s, U17s, U18s and U19s all in attendance.
Under-21s goalkeeping coach Thomas and Under-19s coach Smith will be joined there by Tim Dittmer, who recently joined The FA from Manchester City as goalkeeping coach educator.
Orient goalkeeper coach Kevin Dearden was delighted for Grainger to get the call up.
“We’re obviously delighted for Charlie to be involved in the England set-up again,” said Dearden.
“He’s been with them a couple of times previously and it’s great that they still have their eye on him. Hopefully now he can show them the progression he has made having had his first taste of men’s football having played at Cray recently. It’s always a nice bit of kudos for a club like Orient to have players in the international set-up in any shape or form.”