The five-eighth, who has just completed a disappointing and injury ravaged season will call Kiwis coach David KIdwell this week and tell him he's not going to play in the tournament, according to the Sunday Telegraph.
Foran wants to get himself right for the Bulldogs next season and is prepared to put this ahead of representing New Zealand in the tournament the country will co-host in just over a month's time.
"I tore my quad during the season," Foran told The Sunday Telegraph.
"My back's been pretty stuffed too. I'm busted.
"I saw the Canterbury medical staff last week and we're getting scans to work out the best treatment and best way forward.
"Medically I can't play in the World Cup.
"I played under strength for much of the year at the Warriors and I just wasn't strong enough for NRL football. I've got to get my body right. I really need a big off-season."
With Jesse Bromwich and Kevin Proctor already ruled out of the Kiwis' World Cup team because of disciplinary reasons, the Kiwis will be desperately under strength at the tournament.
Jordan Kahu is also unlikely to play for the Kiwis at the World Cup as he needs to have an operation.
One of their strengths for the Kiwis at the World Cup would have been Foran and Shaun Johnson in the halves, but that looks unlikely to happen now and once again the Kiwis team could have a makeshift look to it.
With the Kiwis having moved on from Benji Marshall, despite having a good season for the Broncos, it leaves Te Maire Martin and Kodi Nikorima as the two likely options to team up with Johnson.
Tuimoala Lolohea, who played for the Kiwis on the 2015 tour to England has already pledged that he'll play for Tonga at the World Cup.
Meanwhile, Foran confirmed to the Sunday Telegraph that the sacking of Des Hasler as Bulldogs coach hasn't changed his plans to move to the Bulldogs next season.
"I'm fully committed to the Bulldogs," Foran said.
"I'm close to Des and I feel for him as a friend. He's a great footy coach and his record speaks for itself."
"I guess I saw it coming from all the speculation," Foran said of Hasler. "Sometimes things don't work out as planned, which is disappointing personally.
"But the Bulldogs have made their decision and all I can do is play. We'll get behind the new coach and hopefully have a really strong year."
Photo by: GETTY IMAGES (Caption: Kieran Foran will join the Bulldogs for the 2018 NRL season).