O'Brien has said in interviews that he doesn't look at the histories and lower grade form of players.
Reporters talked to him about Brodie Jones getting dropped back to Cessnock for a game 2 years ago and O'Brien didn't know about that and wasn't interested in it.
He takes players how he finds them.
Musgrove is classic example of a guy who looks great in training - coach after coach through the grades have loved the guy - but he never looks that great in games. Just a few years ago he was outplayed in every game by a kid from Dubbo named Mitch Andrews - but we kept Musgrove and let Andrews go. In under 18s he was outplayed in game after game by Sam McIntyre, but we let McIntyre go and kept Musgrove. Last pre season Musgrove impressed the hell out of O'Brien by training the house down and was rewarded with a contract.
The flip side of that is Matt Croker. He was our best middle forward in under 20s for 3 years in a row and represented NSW in under 20s, but I don't think he has ever looked great at training. Players like Saulo and Momoisea got plenty of time in reserve grade, while Crokes never got the call-up, despite nearly always outplaying those guys. Now that Crokes is too old for juniors he is setting the standards in reserve grade on the field - but still getting little love.
I'm largely happy with O'Brien making up his own mind on players based on what he sees for himself, and I think he is building the squad he wants based on that - but we have seen a few guys get too much love and a few guys get too little love - based on how good they look in training drills.