NSW Blues legend Paul Gallen has revealed he was surprised after hearing Spencer Leniu was not picked for Game 2 by Brad Fittler.

Discussed as an option off the interchange bench, Leniu was overlooked in favour of Tigers rookie Stefano Utoikamanu.

Gallen admitted that although Utoikamanu is a great young player who will play Origin for years to come, Leniu's aggression is needed in a must-win clash against Queensland.

"I would've picked Spencer Leniu, I would've picked him coming off the bench," he said on 2GB's Wide World of Sports Radio.

"I love Utoikamanu as a player, I honestly think he's brilliant, he's a really good young player (but) to send a young guy up there to the cauldron of Suncorp Stadium in what is a decider for NSW is a very, very big ask for a bloke that hasn't played in any big games before, I don't think he's played a semi-final game."

"You've got Spencer Leniu who's an absolute a weapon, who's played in multiple grand finals, I can't believe he wasn't picked but that's just the way it was.

"I'll be supporting this team no end."

Spencer Leniu was involved in an altercation with Jared Waerea-Hargreaves on Saturday night which saw both forwards sin-binned. However, he was not indicted for the incident and was free to play in Game 2.

A dual premiership winner, Leniu is in the top five players coming off the interchange in the competition.