Brown beat Nadal 7-6, 3-6, 6-4, 6-4 in a thrilling encounter on Centre Court. This was the Spaniards fourth loss to a player outside the top 100 at Wimbledon.
Speaking on his BBC Radio Five Six-Love-Six programme, McEnroe said in his opinion Nadal needed to change his backroom team including his Uncle Toni if he hoped to get back near the top of his sport again.
"Rafael Nadal is one of the great champions – a class act.
“He plays with a lot of effort and energy but, dare we say, is it time for some fresh blood in the Nadal camp? Can we say that? Uncle Toni's going to be upset,” said McEnroe.
"I know that he has had other people – Carlos Costa, Francisco Roig, but they have tried to gently persuade Uncle Toni – who has done a magnificent job since he was a little kid and told him it was a good thing to go left-handed – but clearly at this stage it would appear that some fresh ideas would be in order."
2015 has not been a good one for Nadal, having failed to get past the quarter-finals of the grand slams so far, plus he has only won two tour tournaments this year.
Brown will now face Serbia's Viktor Troicki in the third round at SW19.
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