Expectant father Johnathan Thurston will slip past one of State of Origin's toughest personal records when he plays his 25th consecutive game for Queensland in Sydney on Wednesday night.

The North Queensland star will break a milestone carved out by one of the toughest and fittest men to drag on a Maroons jersey, Gary Larson.

Ironman Larson retired in current coach Mal Meninga's last Origin as a player, in 1994, having made a record 24 successive appearances.

"I'm delighted for Thurston to be breaking my record," said the gravel-voiced former North Sydney Bear who ploughed his way through almost 900 tackles in those 24 Origins.


"He's has been a wonderful player for the Cowboys and for Queensland and an ambassador for the game of rugby league the way he conducts himself around young fans.

"I'm just glad a winger isn't getting it because they are underworked and overpaid."

Thurston has not missed an Origin game since his winning debut at halfback alongside Darren Lockyer in the first match of the 2005 series at Suncorp Stadium.

His partner, Sam, is expecting their first child, with the baby due three days after Thurston is slated to break Larson's record at ANZ Stadium in the first game of this year's series.

Coach Mal Meninga said this week he hoped Thurston's partner would do the right thing by Queensland and deliver their baby after the game.

"We've got everything crossed the baby doesn't come too soon - and hopefully Samantha has her legs crossed as well," Meninga said.

Thurston rated passing the mark of Larson, someone so highly regarded by players for his amazing toughness, a "huge honour".

"I have been blessed to play for Queensland and with so many great players," he said as the Maroons stepped up preparations to make it eight straight series wins.