"I thought the two locks played pretty well last week," he said. "In South Africa you can run out of juice late so we might tactically think about bringing some guys on late like we did last week with Luke and Charles and Paddy which will give us impact late and give us some petrol in the tank.
"We think Charles has a little bit more impact at 15," Kirwan said of Piutau. "He's come into the side a little bit late as the All Blacks do, but we feel he did well for us last week. We just need him to get the ball in his hands a little bit more this week. He's one of our leaders so we think at fullback he'll be a little bit more influential."
Blues team to play the Stormers at Newlands on Sunday, kick-off 4.05pm is: Charles Piutau, Ben Lam, Hamish Northcott, Francis Saili, Tevita Li/Lolagi Visinia, Ihaia West, Jimmy Cowan, Jerome Kaino (c), Brendon O'Connor/Luke Braid/Akira Ioane, Steven Luatua, Hayden Triggs/Patrick Tuipulotu, Josh Bekhuis/Tuipulotu, Angus Ta'avao/Charles Piutau, James Parsons, Tony Woodcock. Reserves: Matt Moulds, Greg Pleasants-Tate, Ofa Tu'ungafasi, Sam Prattley, Charlie Faumuina, Angus Ta'avao, Patrick Tuipulotu/Triggs/Bekhuis, Braid/Iaone/O'Connor, Jamison Gibson-Park, Dan Bowden, Visinia/Li.