Speaking ahead of Friday night's clash with Port Adelaide - O'Brien's 100th match - Malthouse said O'Brien had surpassed expectations since his selection in the 2005 NAB AFL Rookie Draft.
“He's a very, very good footballer,” Malthouse said of O’Brien.
“I'm not here to pick the All-Australian side, but if he's not considered for that half-back, back pocket position, I'd be very surprised.
“He really has made it his own.”
Malthouse said the 23-year-old, who paid for his own airfare from Perth to try his luck at making it on the Pies’ rookie list, had gradually improved by focusing on one area of his game at a time.
“We’ve known the capabilities he’s got in the mind,” Malthouse said.
“He’s just got better [and] better, and he’s now in our leadership group.
“I’m not suggesting for a moment that he should be the captain or vice-captain of this football club but down the track he’s an ideal candidate for it, because he just takes everything in proportion so seriously - on ground, off ground.
“And then he’s able to work his life around several issues, which I think completes the person ... Harry’s able to balance his life, which I think is so important.”
While Malthouse was generous with his praise on O’Brien, he said midfielder Dale Thomas - who will also play his 100th game against the Power - had been just as effective despite the high expectations lumped on him given his high draft selection.
“Don’t underestimate Dale’s contribution to this football club either,” Malthouse said.
“I think it’s been totally outstanding. Both boys should be very much praised equally for their contribution.”
