James Mortimer 14.Aug.2012Getty Images
The Blues midfielder and last season's incumbent All Blacks second five-eighth was selected in the World Champions squad to play Ireland during the Steinlager Series, but did not play.
Williams started all three tests, and put in a brilliant performance in front of his home crowd in the third international against the Irish.
Nonu is expected to start in the upcoming tests, but the number 12 could be shifted out to centre, with Williams likely to run out at second five-eighth.
Williams finished the Investec Super Rugby season as arguably the best in his position, with a championship to boot, and has effectively answered a call for help from the All Blacks.
With Conrad Smith and Richard Kahui out of action, recent plentiful stocks at centre have become scarce, and while Williams is off to Japan in the coming weeks, he will be eligible for selection for the first two matches against the Wallabies.
While Tamati Ellison and Ben Smith have been talked about as potential options in the midfield, the opportunity to play two of the most physically impressive centres in world rugby may be too good to pass for the selectors.
Nonu has played first class rugby at centre, even though he has made second five-eighth his own, at least until Williams breakthrough season with the Chiefs.
It is likely he, and not Williams, would be shifted out.
Even if Nonu and Williams do start, Conrad Smith is expected to recover from his eye injury midway through The Rugby Championship, and the Hurricanes captain is likely to be rushed back into the starting team.