The New South Wales Blues have confirmed their 19th and 20th man for State of Origin Game 3 on Monday afternoon, and it's come straight out of left-field.

While many could have tipped the addition of Parramatta Eels' fullback and representative utility option Clint Gutherson to the squad, not many could have seen the call-up for Stefano Utoikamanu coming.

Utoikamanu, widely touted as one of the hottest young prospects in the game is just 21 years old and had a big-minute performance in the Tigers soul-crushing loss to the South Sydney Rabbitohs on Sunday afternoon at Leichhardt.

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Despite being just 21, his size and agility have made him a threat already, and improvement has been a constant trend surrounding the man-mountain.

But what makes the decision more intriguing is that Utoikamanu is now the first choice forward reserve if the Blues run into any injury problems during camp. The Auckland-born Parramatta junior made his debut at the Eels last year in Round 9, and has made 16 NRL appearances, starting just a handful of times.

Following news this morning that Daniel Saifiti has pulled out of the squad due to a rib cartilage injury, Dale Finucane was promoted onto the bench, leaving Nicho Hynes as the only reserve.

NEWCASTLE, AUSTRALIA - AUGUST 19: Daniel Saifiti of the Knights looks on during the round 24 NRL match between the Newcastle Knights and the Melbourne Storm at McDonald Jones Stadium on August 19, 2017 in Newcastle, Australia. (Photo by Ashley Feder/Getty Images)

Not calling up a second forward alongside Saifiti indicates Fittler will play the youngster if it comes down to it.

Gutherson's chance of representing the Blues, even in the event of an injury, seems limited though, given he was called into the squad with Hynes already there.

The dead rubber match will be played next Wednesday night, with the venue still yet to be confirmed by the NRL.