"The great thing about the draw from many perspectives is that first or second, we kind of know that when you've got a draw when you go into a tournament and the top four teams in the world currently are going to play each other in the quarter-finals, you know it's going to be a monster game," said Foster.
"Nothing's going to surprise us now and we're going to be ready for whoever it is.”
New Zealand have responded admirably since losing the tournament's opening match 27-13 to hosts France.
Thursday's 73-0 thrashing of Uruguay meant the All Blacks have scored 36 tries and 240 points in three matches since losing to France.
"I think we've responded well from the first game, we took lots of lessons out of that," said Foster.
"We've dealt with each challenge we've had in meantime. I believe we've grown our game to the point of going to this quarter-final really well prepared and feeling whatever happens, whoever we play, it's going to be a massive game and that's what the quarter-finals are supposed to be like."
'Amazing World Cup’
For Uruguay it turned out to be one game too far.
They could not match their performances in previous competitive defeats against France, who did not manage to earn a try bonus point, and Italy, nor their victory over Namibia.
Captain Andres Vilaseca put that down to the All Blacks' brilliance and said facing New Zealand was a different proposition to France and Italy.
Uruguay had been only 13-12 down 10 minutes into the second half against France before losing 27-12.
And they actually led Italy 17-7 at half-time before an untimely yellow card cost them dearly and they shipped four tries in 15 minutes to lose 38-17.
"I think it showed that there was" a difference between New Zealand and the rest, said Vilaseca.
"We were up against the best team in the world. It was our fourth game and the physical and mental fatigue started to play its role.”
It took New Zealand 20 minutes to score their first try through man-of-the-match Damian McKenzie, but after that the points flowed insatiably.
"The truth is that as the game progressed New Zealand found it easier to find spaces," said Vilaseca, who was nonetheless delighted with how their World Cup has gone, with the South Americans beating Namibia 36-26.
"We can be very proud of ourselves. I think we had an amazing World Cup," he said.
"Playing France, the host nation, Italy, Namibia -- we won -- and now New Zealand, playing the best team in the world.
"It's about learning and trying to give our best and trying to grow the sport in Uruguay. It has been amazing."
'We finished strong’
Foster acknowledged that the first 20 minutes had been frustrating.
"It would have been easy to get frustrated after that first 20 (minutes), but we didn't, hung together well, got the bonus point by half-time and finished strong," said Foster.
All Blacks captain Sam Cane paid a special tribute to veteran lock Sam Whitelock, who chalked up his 150th cap and record 23rd in the World Cup, passing the previous mark set by compatriot Richie McCaw and England's Jason Leonard.
"It's phenomenal achievement, it's a lot of Test matches," said Cane.
"He's someone who optimises professionalism and a lot of work he puts in during the week is relentless and I think it's part of the reason he's had such a long and successful career."