Sydney Roosters premiership winner Sonny Bill Williams has reportedly committed to New Zealand’s Rugby League World Cup defence just a day after saying he would miss the end-of-year tournament to spend time with family and friends.

Fairfax Media reported on Tuesday night that Williams had phoned Kiwis coach Stephen Kearney to declare he wanted to be a part of their campaign.

The move is sure to fuel speculation the dual international could re-sign with the Roosters for the 2014 NRL season.

Earlier on Tuesday, Kearney said the back-rower was unavailable “due to other commitments”.

“What they are, at this stage we would all like to know,” Kearney said.

While Williams wrote on Twitter: “Wishing the kiwis in their title defence, having my first break since 2008. Looking forward to spending time with fam n friends,” Williams wrote on Twitter.

But it appears Williams may have changed his plans.

Williams’ inclusion would be a huge boost to the World Cup and to the Kiwis’ hopes of successfully defending the crown they won in 2008.

He was believed to be on the verge of returning to rugby union with Super Rugby’s Chiefs next year, but if Williams does join New Zealand’s squad the NRL will be understandably confident he might be on deck in 2014 to help the Roosters defend their title.