His comments come amid rumours that the Selhurst Park club are opening talks with Aitor Karanka, who coached underneath Jose Mourinho at Real Madrid.
The 40-year-old former Real and Athletic Bilbao defender has never been in sole charge of a club or worked in England.
Millen feels that Palace's situation, which sees them at the foot of the Premier League with four points after 11 games, warrants the recruitment of a manager with top flight know-how.
"If it was my choice it would probably need to be a Premier League manager that knows this division and with his experience, knows how to win football matches," Millen said.
"Because there is an art to it. You look at the managers who survive in this division and find a way of winning matches. That would be the ideal situation. But if that's not the case, then you get the man in who you think will take this club forward."
Eagles goalkeeper Julian Speroni admitted to being in the dark over the identity of the club's next manager.
"I check the internet every day to see if anything is going on," said the Argentine stopper.
"The character of the manager does not matter, as long as they come in with a positive mentality, the idea of staying in this division."