Sonny Bill Williams needs to play just one NPC match to be able to be available for the All Blacks end-of-year tour.

Speaking to stuff.co.nz, New Zealand Rugby Union chief executive Steve Tew went on to explain the All Blacks' policy with regards to eligibility.

'His contract allows for that and our policy allows for that provided he plays in the NPC,' said Tew. 'Whether that's the right thing for Sonny Bill Williams to go on the tour, or whether he's good enough to go on that tour are for other people to decide. The policy is a little open ended – just that you play in the preceding competition. I guess you could say 10 minutes off the bench might tick the box.'

Williams is currently turning out for the Sydney Roosters in Australia's NRL and his availability will depend on the progress of his club. With the grand final scheduled for 5 October, it seems unlikely that he will be able to feature for the All Blacks anytime before the end-of-year tour.

He has signed a two-year contract with the New Zealand Rugby Union and the Chiefs with the hope of appearing for the All Blacks at next year's World Cup, but it remains to be seen what All Blacks coach Steve Hansen's position is on the matter.

'The more important questions are what is the right thing for him to be in the best shape possible for rugby in 2015 and who are the best players to deliver the outcomes [All Blacks coach] Steve [Hansen] wants to deliver,' Tew continued.

Current Counties Manukau coach Tana Umaga, where Williams will play for in the NPC, is excited by the prospect of having the cross-code star in his squad.

'All I know is if he wants to go on the end-of-year tour he’ll have to play some time for us this year,' Umaga said. 'We’ve been prepared for that. If he is feeling good and wants to go on the end-of-year tour after his time with the Roosters then I’m sure we’d have no qualms making time available for him to get on the field.'

Photo: Simon Watts/Getty Images