Houllier said: "I told Bannan the best players in the world are even smaller than you.
"Xavi, Iniesta, Messi, Pedro. You can watch and wonder if they are playing in the youth team sometimes.
"They have fast technique and young Barry has all of that.
"The Premier League has got more physical but it is not about a matter of size.
"Obviously you need size in some positions but it's also a matter of commitment and physical commitment. Barry is competitive."