The Manchester United manager says the former Barcelona star will have to prove himself for first-team football.
The former Barcelona 'keeper signed for United on a free during the January transfer window but has not made any first team appearances so far.
In fact, he has made just one appearance for United’s under 21s side since the move, in which they beat Liverpool in a 2-1 win.
"When you are out for more than a year, first of all you have to show yourself at a lower level," Van Gaal said.
"He has to do it in the second team. Like Ashley Young is doing that, like Michael Carrick has to do that. It is always the same. I think it is normal."
The goalkeeper has only just returned from a serious knee injury he suffered while still at Barcelona, but is unlikely to be happy to be number two at Old Trafford, having declared that no-one is happy to be a number two when he arrived.
Unfortunately for him, he will have to displace Spanish goalkeeper David De Gea if he is to become number one, and that is unlikely to happen any time soon.
De Gea has been in fine form for United for several seasons, sparking firm interest from Champions League holders Real Madrid, and is firmly established as first choice for Van Gaal as well.