Young impressed operating just behind Darren Bent when he replaced Rooney for the second half of the friendly international in Denmark last week.
Houllier is aware Young still has room for improvement in that role after switching him from the wing with good effect after taking over as Villa manager.
But he feels the former Watford player will not shirk away from the battle to become an England regular.
He said: "Can Young compete for the Rooney role with England? You have competition everywhere, national teams, clubs teams, everywhere.
"If you are a top professional player, you know there is competition everywhere, where you play, and you need to accept that. But competition makes you grow. It's a challenge and Ashley wants to learn."
Source: PA
Source: PA