But Allardyce has puzzled with Wayne Rooney, Harry Kane, Jamie Vardy and Daniel Sturridge for his basic test as England boss.
And the former Sunderland manager wants Rashford to net his stripes with the youth team.
He said: “I think that begetting international experience in the u21s will be invaluable for us later down the line and I believe if he plays for Manchester United on a regular basis — and is breaking into that rig — then he’ll be in my squad.
“But because of his inclusion only as a sub I think the value of inducing a full game with Gareth will be invaluable for us a bit like Harry Kane and in the flesh like that in the st.
“He made a massive im ct last occasion yes, but he’s only a young man so let’s not heap too much pressure on him yet.
“Let him go and have a feel and it is hoped he’s a star for them.”