Cusiter is one of three Scots in Sir Clive Woodward's party, along with Gordon Bulloch and Simon Taylor, and the Borders scrum-half is the youngest of the Scottish contingent at the age of 22.
The 16-times capped international has enjoyed an astonishing rise after turning professional two years ago.
But, despite the presence of the more experienced Matt Dawson, Dwayne Peel and Gareth Cooper ahead of him at scrum-half, Cusiter is relishing just being a part of Woodward's squad.
He said: "Hopefully, I can get the best out of myself playing with world-class players.
"I just want to keep reproducing that and play as well as I can, that's all I can expect of myself."