The Three Lions will play at Wembley tomorrow, but could be without left-back Luke Shaw, who is struggling with illness.
When asked in a press conference which players have impressed him, Gerrard said: "The young lads have done fantastically well and we have two great players fighting for every position in the starting XI.
"Everyone is capable of being picked in the starting XI and that keeps the standard high. Everyone is pushing for places and it's a chance to impress against Peru. Hopefully we all come through the game."
England will begin their campaign against Italy in Manaus on June 14.