LONDON • The fallacy that John McEnroe would simply be working as a coaching consultant to Milos Raonic was exploded within approximately five minutes.
McEnroe's rage for perfection, even at the age of 57, still takes some curtailing.
He may have joined his former arch-rivals Jimmy Connors and Ivan Lendl, as well as Boris Becker, Stefan Edberg, Michael Chang and Richard Krajicek in the bracket of "celebrity coach", but McEnroe was never just going to stand by quietly.
Raonic, tennis' world No. 9 who serves as hard as anybody on the professional circuit today, is aware of his weaknesses. Although he was a Wimbledon semi-finalist two years ago, he struggles to back up his greatest weapon on grass because he is tentative when approaching the net to volley.
Taking a break from his preparations for this week's Aegon Championships at London's Queen's Club, where he is the third seed, the Canadian said: "Last Monday we stepped out on court for the first time. John said, 'Milos, start with a hitting partner and we'll see.'"
"Almost straight away, he grabbed the balls, got on court himself and ended up hitting for 31/2 hours. I can't imagine there are many guys his age that can play so many hours of tennis a week. He wants to make a difference."
Raonic was not McEnroe's first choice when the tennis world's most in-demand commentator, who also has his own academy on Randall's Island, New York, decided he had time to work with a leading player.
Although he will not admit it in as many words, McEnroe was waiting for a call from Andy Murray but it never came.
McEnroe and Raonic both have friends in the family of Jann Wenner, founder of Rolling Stone magazine, and a mutual interest in contemporary art.
They have played social tennis a couple of times in New York, but Raonic, 25, would not have thought of McEnroe, the winner of three Wimbledon titles, as a friend.
With the youngest of McEnroe's six children now aged 17, there is less demand on his time for parental duties.
He worked as a coach once before to Becker 23 years ago, but it was a short-lived arrangement and McEnroe recalled: "Basically, he didn't listen to a word I said."
Things are different with Raonic, who hangs on McEnroe's every word.
"He's a good kid, very professional, very dedicated, and he wants to get better," said the American. "A type of kid who appears, at least to me, to leave no stone unturned. He's like Murray in that respect. He's going to do everything to get as good as he can be."
The new coach will fulfil his commentating duties with the BBC and ESPN at Wimbledon, but this week will devote his time to his new role.
"The timing made sense to me. There was an opening in my schedule so I thought to myself, 'Name six or seven guys that can win Wimbledon.' I put Milos as one of those guys. At the moment he's the sixth or seventh, but things can happen."
Raonic likes to think of himself as "the CEO of Milos Raonic Tennis Inc". McEnroe has no problem with that, though fireworks are always possible when he is involved.
"You've got to figure out a way to get inside these guys' heads, which is easier said than done," said McEnroe. "You've got to be honest. I'm not going to sit there and show no emotion like (Ivan) Lendl did when Andy won Wimbledon. Milos knows that."
THE SUNDAY TIMES, LONDON