Another option was to leave Ranger at centre for a confrontation with Hurricanes captain Conrad Smith, and pick Waisake Naholo on the wing.
However, his only previous match against the Bulls did not go well. He suffered under the high ball and the Blues do not want to offer Beauden Barrett a repeat kicking target.
Shifting Ranger to the wing will assist the Blues' attacking choices and bolster their defence in a match which is likely to have a huge up tempo content.
For much of the year Ranger has instigated counter-attacks with his ability to turn over ball at breakdowns, run out of defence or offload in tackles. The Hurricanes will have to be brave to kick to his wing while Saili and he will work hard to unsettle Smith.
The Blues' other selection discussions will be about their front row combination. Charlie Faumuina's season exit meant Angus Ta'avao shifted into tighthead, James Parsons stayed at hooker and Tim Perry was used at loosehead against a very strong Highlanders scrum.
There were some dramas and there will be debate about Perry or Tom McCartney at loosehead.
Former captain Keven Mealamu is ready but Kirwan confirmed he will be used from the bench and then considered for a start after the team's bye. His health and full fitness was even more crucial now that Faumuina had been lost.
"There is no point in risking him [Mealamu], he is fundamental to us because of his experience," Kirwan said.
The Blues beat the Hurricanes 34-20 when the sides met in the opening round of the competition at the Cake Tin. Since then the Blues have won two more matches while the Hurricanes have won their past four.
The Blues had an intense session yesterday concentrating on the defensive patterns they will need to combat the Hurricanes' width and attacking prowess.
"I think they are the best attacking side in the competition at the moment," said Kirwan.
"They can attack from anywhere, they have some really potent weapons with Julian [Savea] out wide and Conrad [Smith] who is running the show so we need to be on our game defensively. We spent more time on that today."
The Hurricanes were vastly rearranged because of injury when they beat the Waratahs in the last round but it appears that Victor Vito (calf), Ben Franks (back), Dane Coles (hand) and Karl Lowe (bereavement leave) are all back in the selection frame this week.