The 19-year-old midfielder is set to start Monday night's third round tie, where Everton will aim to avoid a giant-killing, and it will be a chance for him to prove his ability.
But Moyes has no doubts about Barkley's skill and thinks it is only a matter of time before the youngster replicates the rise to stardom of former Everton sensation Rooney.
"We have to remember Ross is a young boy and we're bringing him on," said Moyes in the Daily Mirror.
"He missed a bit of football but I will continue to edge him nearer to our first team.
"The boy is going to be a very good player, and I have always thought he will play for England but we must be wary."