MacDonald especially welcomed the experience and craft that All Black Nepo Laulala brought to the tighthead side of the scrum.
"He's a renowned scrummager, we know he's very powerful in the scrum. He's physical, especially around defence.
"He's a good pro, and he's working hard, and he's going to be a great addition. We're excited to have him in the Blues jersey, that's for sure," he said.
"He put a few big shots on last weekend, so he doesn't mind getting into that physical stuff."
Samoan international James Lay has taken advantage of Alex Hodgman's absence due to injury to earn a start at loosehead prop. An Auckland prop in 2016, he played 14 games for Bay of Plenty in the 2017-2018 seasons before heading to England where he played for Pat Lam's Bristol side. He has played 10 Tests for Samoa.
MacDonald said, "James has performed well for us in the pre-season, and Karl is going well, and he's got unique strength, especially around scrummaging.
"It's around balancing our team to give us an all-round 80-minute performance and we feel that in this game, in particular, we're going to need, and having Karl coming off the bench to help finish the game gives is more strength, so it's something we want to try to utilise," he said.
"We're missing one of our All Blacks props in Alex, and he's a big loss to us.
"But we're comfortable with the pack we've put out. It's a powerful pack. It's a big team. It's probably one of the biggest packs we've put out, and we've got some really good depth off the bench.
"So, it's a good position to be in, and the old adage about it being a big battle up front is definitely relevant in the weekend, because I know they're a physical pack as well," he said.
Blindside flanker Akira Ioane was looking to build on the progress he made last year.
"He's turned up in great nick, he's looking really quick and he's hungry. He's pushed forward in the off-season, he hasn't used that time to slacken off at all. He's had a taste for the All Blacks and I think he wants more so that's exciting if you're a Blues fan," he said.
MacDonald said the emphasis referees in pre-season games had put on any offside play was good to see. Faster play resulted and the Blues had put work into that area and he was confident they had their heads around the requirements.
That would be important, especially in the early games when fitness was tested and it was a challenge for players to get back onside.
It had been something the referees started with last year, only to reduce the emphasis, but they had said they would be applying the laws for the whole season.