Leger, too, is playing in an unfamiliar position; he played No10 or N12 for the New Zealand Under-20s, but is adapting well further out in his first season with the Blues after shining during their run to the Brisbane Global Rugby 10s title at the start of the year.
Against the odds, perhaps, it worked in Sydney, but Umaga will have no hesitation about changing things up to make room for Williams, who has played 46 tests for the All Blacks but only three matches for the Blues this season.
He is a game-breaker who will add much-needed quality to a backline which will have its hands full against Beauden Barrett, Ngani Laumapi and company on Friday. Ben Lam, a former Blues wing with 12 tries in nine matches for the Hurricanes this season, will also take some stopping.
If Williams starts at No12, Ioane will likely move to centre – his preferred position.
Williams partnered George Moala in the season-opener against the Highlanders, missed the next match against the Chiefs with a knee injury and partnered Ioane for the next two – the win over the Lions in Johannesburg and defeat to the Stormers in Cape Town where he injured his wrist.
It has been a long and presumably frustrating time on the sidelines for Williams. If the 32-year-old does get an opportunity, he, along with all his teammates, will need to put in a special performance to beat a Hurricanes team with only one defeat this season.
There is also the Eden Park factor to consider; the Blues have yet to win in four times of trying at their former fortress this season.
But, again on the plus side, there is also a possible return for outside back Melani Nanai - an outside back with real pace and the ability to beat defenders.
All of a sudden, Umaga has options and is presiding over a team with an infusion of confidence from their victory over the Waratahs. They may be out of the playoffs themselves again this year but they still have a major part to play in terms of where other teams finish, and in particular the Hurricanes and Crusaders.
The Blues' penultimate game of the season is away against the Hurricanes which comes in between home and away fixtures against Scott Robertson's men.