Bennell, 20, won the Polly Farmer medal for best on ground in the All Stars' 50-point win over Richmond on Friday night at Alice Springs' Traeger Park.
The dazzling performance in the pre-season showpiece follows on from the young West Australian's strong 2012, where he placed second in Gold Coast's best and fairest after playing all 22 games and putting his homesickness behind him.
"He's starting to realise the work rate and professionalism and dedication you need to succeed at this level and he's building a career not for one, two or three years, but to get a 10-plus year career out of it. I think it's sunk in," O'Loughlin said.
"He's got a really good tank so he's able to run. His running capacity has improved out of sight.
"I've known Harley since he was in the AIS Academy, I was his mentor there and to see him come on … He could be one of the really good players in the AFL, a real top liner."
Bennell's game involved some classy work along the wing, a collection of nice disposals and a goal in the final quarter.
He took best on ground honours from Western Bulldogs' forward Liam Jones, who started the game with two goals and showed positive signs across half-back and in the ruck.
For Richmond coach Damien Hardwick, the scale of the defeat was disappointing but he left Traeger Park pleased with what he saw from his young players.
Draftees Nick Vlastuin and Kamdyn McIntosh earned his praise while second year forward Todd Elton impressed with some strong marks.
Hardwick said the exhibition match had been all about experimentation for his team.
"It was always going to be a game where we were going to see what some of the players could do," Hardwick said.
"We were always going to try things, at various stages we put a few blokes behind the ball and then we tried it the other way.
"We had relatively young squad out there, just to get them in tune with what we're trying to do going forward."
Captain Trent Cotchin, Brett Deledio, Jack Riewoldt, Alex Rance, Ivan Maric and Bachar Houli were among the Richmond players to sit out the game.
Hardwick said they were simply not yet ready to play but would likely figure in the Tigers' first NAB Cup double-header with North Melbourne and Melbourne on February 22.
"It's always just a management issue at this time of year. You've always got to manage minutes and it was just one of those decision we made," he said.
"Most of those guys will play NAB one a couple of weeks away. Touch wood we get them through. And the guys in our rehab group, it's getting smaller and smaller every time, so come NAB one we'll pretty much be a full squad."
Harley Bennell is a midfielder in NAB AFL Fantasy. He averaged 85.05 points in 2012. Register your team at our AFL Fantasy Hub.
Jennifer Phelan is a reporter for AFL Media. Follow her on Twitter @AFL_JenPhelan.
