The All Blacks won the first test 23-13 at Eden Park last week with a rusty performance, though Bru also said that his side had been less than clinical in the match and he expected better in Christchurch on Saturday.
"The problem is that the player belongs to the club and when we meet with the French team we have only one week to work collectively on our organisation, offence, defence, work on the breakdown, work on set pieces," Bru told reporters at the team hotel ahead of the second test in Christchurch.
"There is a lot of things to do with not much time.
"I don't know if we are stronger but we have had one more week together and we have more accuracy on all aspects of the game."
Their inefficiency of execution last week manifested itself in the set-piece, particularly in the scrum after they had mistimed their engagement on the first couple and drawn the ire of referee Wayne Barnes, he added.
"Our scrum was really poor," the former France hooker said.
"We were not clever enough in the way the referee wanted the anticipation (of the contact) at the first scrum and I think that had a factor in the psychology of the scrum for the rest of the game.
"It was our responsibility to give him a bad image of the first two scrums.
"Referees are human beings. He didn't play in the scrum, but I think after what he saw in the first scrum it had an influence on his judgement for the rest of the game."
France coach Philippe Saint-Andre brought back tighthead prop Nicolas Mas to face Wyatt Crockett in the second match and Bru said the 60-test veteran would give his team confidence but he was not the total answer to their issues.
"He has a lot of experience and will give guys around him a lot of confidence," Bru said.
"But Nicolas Mas on his own won't do anything if we don't have much better organisation, discipline and respect of the referee's calls.
"I hope with more organisation, discipline and Nicolas Mas, we will have a better performance in scrummaging."
The lack of discipline at the scrum and the lineout had hurt the French, Bru said, and they had concentrated on tightening up that aspect of the game after they had worked specifically on the breakdown in the build-up to the first test.
France shaded that aspect of the Eden Park match and they expected the All Blacks would work on that this week, Bru said.
"Last week we were quite good (at the breakdown). We spent quite a bit of time on it last week," he said.
"This week, we have tried to work on set pieces, because New Zealand hurt us on that last week.
"I hope that we keep the intensity in the breakdown but New Zealand have also had one more week and I expect a tough battle there (because) I think the All Blacks will also be more accurate."
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