USARL chairman Peter Illfeld said Kimmorley had advised him he would need to relinquish his position as assistant coach to Brian McDermott to care for his four young daughters, Maddie, Mia, Avy and Ivy.
“On behalf of the USARL I have passed on to our USA Hawks assistant coach for the Rugby League World Cup, Brett Kimmorley, our deepest sympathy and condolences on the passing of his wonderful wife and mother of their four daughters, Sharnie," Illfeld said. "We are all very saddened for Brett and his daughter’s loss.
"Brett, unfortunately, has advised his need to step down from his role with the need to be home to look after his girls.
"We sincerely thank him for being part of our team and should time permit change, that we would be honored for him to return."
The rugby league community has rallied behind Kimmorley and his family since Sharnie, 38, lost her nine month battle with brain cancer last Thursday.
Among those to offer support were NRL chief executive Todd Greenberg and the Newcastle, Melbourne, Cronulla and Canterbury clubs Kimmorley played for during his illustrious career.
Since retiring in 2010, Kimmorley has moved into the media and coaching, and joined the USA Hawks coaching staff last October as an assistant to McDermott, who is the Leeds Rhinos mentor.
The former Australian and NSW State of Origin halfback has also worked with Canterbury and Parramatta, as well as being an assistant coach at Canberra and having been in charge of Wests Tigers Under 20s.
He last year coached Wests Devils to the Illawarra Rugby League grand final.
Illfeld said the USARL would appoint a replacement for Kimmorley to assist McDermott with preparations for the World Cup.
The Hawks play Fiji and Italy in Townsville on October 28 and November 5 before travelling to Port Moresby to meet Papua New Guinea on November 12.
This article first appeared on RLWC2017.com