Facing prospectively 15 Tests this year, it was one of the busiest seasons on record. The Tonga Test and the two against Fiji in Dunedin this weekend and Hamilton next week would be important in assessing the make-up of the side for the Bledisloe Cup and Rugby Championship campaigns, ahead of the northern hemisphere tour later in the year.
"This series is a very important series for us from that perspective," Foster said.
"So we've got some big calls to make, but we'll worry about those calls after we see these three games.
"The great thing is we've got the chance to give some people some opportunity to put their best foot forward during the training week and how they prepare. It's pretty competitive," he said.
Foster said they were delighted to be underway with the season after an intense eight days getting ready for the Tonga game.
He said while a lot of attention would focus on the 102-0 score, they were delighted to be back playing rugby and against the Pacific nations.
They were aware of how tough it was for Tonga to get organised and cope with quarantine and Covid, but it was still good to see the two countries playing again.
"A big hand from us to them for the way they prepared in a really difficult situation," he said.
Tonga were put in a compromised position, but they were keen to play, and they deserved credit for that, Foster said.
"I'd like to think we're not just going to focus on the scoreline and say this was a game that shouldn't have happened because, I think, for the Tongan people, it was an important game, and it was equally important for us to go out there and start what could be a long year.
"In today's environment you take what you can get," he said.
Foster said Tonga always played well at World Cups. But in the years between, the World Rugby calendar made it difficult for their No1 team to play consistently.
It had been a good performance for the All Blacks. There were occasions when they were under pressure, but Foster was happy with how they fought their way out of that without getting frustrated.
"Overall, I was really pleased with a lot of the skill level and some of the shape that we put out on the park," he said.
Foster said the four debutants, second five-eighths Quinn Tupaea, halfback Finlay Christie, prop George Bouwer, and flanker Ethan Blackadder could be proud of their performances.
Five-try scorer wing Will Jordan, who made his starting debut, had shown his speed, but also his ability to get into the right position at the right time. On the other wing, George Bridge didn't have as many chances but would be better for the outing.
Foster said he was pleased with fullback Damian McKenzie's return.
"He looked calm. I think in the last two months his decision-making at the back has been really accurate. He's gone from the guy that just did the dazzling runs, and getting some wrong, to now he's distributing, he's kicking well, he's coming in and giving us that two-sided attack that we love to have," he said.
Captain Sam Whitelock was pleased with the way the leaders kept the team on their goals while there was growth in several of the younger players.
Flanker Dalton Papalii was an example of who played well.
Whitelock said it would have been better if Tonga had more of a build-up for the game, but at the same time, the preparation had been compact for the All Blacks.
Whitelock said having another Super Rugby franchise in New Zealand, Moana Pasifika would be good. While it might test depth, it would develop football as well and improve the depth of all the Pacific nations.
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