Lood de Jager was sent off against France and Franco Mostert versus Italy, but the Springboks won both those games with 14 men.
Mostert’s red was later rescinded, while De Jager lost an appeal, but Kolisi says that physicality is part of who they are and what has taken them to back-to-back World Cup titles.
Asked if discipline could be a deciding factor this weekend, Kolisi said they had been working hard on their tackling in particular.
"We want to play with 15 men," he told reporters on Friday. "We’ve been working really hard on all the controllables, level changing, wrapping, doing that over and over.
"We’re an aggressive team, and we can’t take that away, which is why we work so hard to make sure we stay on the field."
Kolisi knows his side will have to be at their best to win in Dublin.
"Ireland are a really good team and we have struggled for many years in terms of winning here. We’re going to need everybody. It’s all about taking opportunities," he said.
"The games we’ve lost (against them) by one or two points or three points, we’ve had chances at the end and didn’t take them. We’ve learned a lot and worked really hard this week."
Kolisi also praised Leinster lock RG Snyman, who will earn a 50th Springbok cap this weekend.
"I’m really happy for him," he said. "With everything he’s been through (injuries), he could have given up any time. Credit to the unions who stuck with him. Even when he wasn’t with the group, he was messaging us, supporting us.
“He’s one of the most talented guys in the squad. A big human being, hard to put down, and the way he offloads … we allow him to be who he is. He knows the team comes first, and that’s what makes this team special.
"I’m happy for him and his family, and hopefully we can make it special for him."