"We'd like to see Waisake with a bit more game time," Foster said. "It was pretty hard to assess his last game wasn't it? He started with a hiss and a roar and did something pretty spectacular which we know he can do and then he looked a bit rusty around the park in some of his roles. But that comes when you're out for some time."
The good news for the All Blacks is that midfielder Ma'a Nonu is likely to be back in the frame for a starting spot for his 100th test after missing the Georgia match due to a minor shoulder problem. Beauden Barrett, ruled out with whiplash, is also likely to be available.
Foster re-stated the All Blacks' belief that they are in a good position in the tournament so far despite looking rusty as they attempt to work on different aspects of their game against the so-called weaker teams in their pool.
"I'd say we're in a really good spot. We've had three tests, each with different challenges in them," Foster said.
"We're in a tournament with a job to do and we've done the job and we know there are some areas that have been clearly identified by us that we need to get better at. But this group, when they focus hard on something, can make adjustments pretty quick.
"We're learning well ... we're adapting, and we're still chasing the game we really want to get to. That's not a bad place to be at."
Tonga lost 45-16 to Argentina in Leicester yesterday but showed they have the ability to pressure the All Blacks. Foster is expecting them to take Georgia's lead in certain areas. He refused to elaborate but they will almost certainly be in the scrum and their tactics on defence whereby they had a lone defender targeting the midfield from an outside-in angle.
"Argentina are playing very well at the moment and are keeping the ball alive which probably got to Tonga a little bit, but we've played a few games against Tonga before and when their backs are against the wall and you think they've got nothing to play for, they turn around and go very very hard at you. We're expecting them to do that.
Foster said of the Tongans using the Georgia tactics as a template: "To that end it will be very valuable for us - to see how much we've advanced in a week."
- Patrick McKendry in Darlington