Captain Christine Sinclair went down hard twice as the Africans showed no mercy on an artificial pitch at Toronto FC's training centre. The resilient Sinclair had the best scoring chance late in the game but could not get a rebound off an Adriana Leon shot past the Nigerian goalie.
Canada's Sophie Schmidt hit the post in the first half.
Canadian coach John Herdman, who spent most of the match yelling instructions from high above on a mobile crane, charitably called it a good learning experience.
"It wasn't the best game, they know that," said Herdman, who was not happy with what he saw. "A couple of players probably didn't stand up the way they should have in this match. They'll be asking themselves questions, because they're honest like that."
"We had a good 15 minutes and that's about it really," he added.
Nigeria, the African champions ranked 33rd in the world, are in Group D — the so-called group of death with the No. 2 Americans, No. 5 Sweden and No. 10 Australia.
Herdman wasn't impressed by any of his players on the day but, after some consideration, cited fullback Alyssa Chapman as doing well. He also said teenager Jessie Fleming, a wisp of a midfielder, contested well.
She took her lumps doing so. At one point, Fleming threw her hands up appealing for help from somewhere after one physical challenge left her lying face down.
"It was a little stressful," Fleming said later of the game. "We probably made it harder on ourselves than we needed to."
Centre back Kadeisha Buchanan, no stranger to mixing it up on the pitch, called the Nigerians one of the most physical teams she had ever faced.
And when the athletic Africans weren't causing damage, the conditions were. Jonelle Foligno, wearing a mask to protect two black eyes sustained before the match, had to leave after an errant ball smacked her on the mask.
The eighth-ranked Canadian women plays No. 6 England in Hamilton on Friday in their last outing before opening the World Cup on June 6 against No. 16 China in Edmonton. Herdman promised a different performance against England.
Herdman used virtually all his players Monday and had to be creative at right fullback with Rhian Wilkinson nursing a hamstring and Marie-Eve Nault pulling up in the warmup. Herdman used Robyn Gayle, Josee Belanger and Emily Zurrer as makeshift fullbacks.
As usual, there was method in Herdman's madness. He selected the Nigerians, knowing that he could face an African side in the round of 16. So he wanted to expose his team to the direct man-marking African style.
"You're not used to that, You don't train like that, you don't play like that. In your clubs you don't play like that ... We just wanted to make sure that they got that experience so it doesn't become a hijack when they're in the actual tournament."
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