The idea seemed a good one when broadcasters here at the Australian Open installed a fixed camera in the stands just a few feet from the players' boxes in the hope of getting an even closer view of the coaches and entourages. Then Ivan Lendl arrived.

Within minutes of taking his seat in Rod Laver Arena for Andy Murray's match against Mikhail Kukushkin yesterday, Lendl reached over and covered up the all-seeing eye.

"I just found it annoying that it was right in our face, so I threw a towel over it and then a hat," Murray's new coach said after his man had booked his place in the quarter-finals against Japan's Kei Nishikori. Asked about the incident by ESPN, Lendl said: "I just figured the camera was a little hot. It was really warm out there. I was actually looking out for you, protecting your equipment."

Lendl does not enjoy or seek attention - "It's not right because it's about Andy, it's not about me" - and must be a source of frustration to the television companies. Team Murray have enjoyed the 51-year-old's sense of fun away from the courts - when asked in an on-court interview to give an example of his jokes, Murray said they were not clean enough to repeat on television - but when he is watching matches Lendl is as steely-eyed and unemotional as he was during his playing career. Nobody took their work more seriously and his attitude remains the same 18 years after his retirement.

Was Lendl getting excited with the sharp end of the year's first Grand Slam event approaching? "I think that would be the wrong way," he replied. "You have to keep the temperature level. I think to get excited now would be a mistake."

Most players practise at the tournament venue on non-match days, but Murray has been working off-site at nearby Kooyong. "I asked Andy about it and he was fine," Lendl said. "I used to do it this way at the French, over here and at Flushing. On any day you don't have to come here it takes less out of you mentally and physically because nobody is tugging away at you. It's just the four or five of us there, nobody around."

He added: "They treat us nicely. Andy can get his physio done there, you get a really nice lunch, it's very quiet instead of being in the rushed atmosphere over here. We have the court to ourselves. I found it beneficial for me."

Do Lendl and Murray go out to dinner together? "It's Andy's call. I don't want to make too many changes. Kim [Sears, his girlfriend] is here. They do their own thing for dinner. I just say to him to let me know whenever he needs me, I'm here. I just go down to the food court, get something to eat and go to bed. If he doesn't need me on a day off I go off and play golf. If he needs me and wants to talk over dinner then we talk over dinner."

The most obvious impact Lendl has had is in Murray's on-court demeanour. There has been almost no screaming in the general direction of his entourage, no running commentaries with himself at the back of the court, no prolonged scowling and grimacing. Asked whether he would like it if Murray started shouting at him, Lendl joked: "I can yell back."

Both men say it is much too early in their relationship to make any major changes to Murray's game. "When you have a player of this calibre, you don't do anything radical, that would be suicidal, crazy, the biggest mistake we could make," Lendl said. "You do a little thing here, a little thing there."

Lendl knows what his major task is: to see Murray over the last hurdle and win a Grand Slam title. "I wasn't hired to get Andy to the quarters," Lendl said. "We all know that. He doesn't need me to get to the quarters or semis. He's done that without me and he could do that without me again.

"That's not to say he's going to win. Nishikori is a good player. You don't get to the quarters by being a bad player now, ten years from now or 20 years ago. It just doesn't happen. Hopefully I can help Andy, whether it's [through him] talking to me, asking for my experience, [or me] helping him a little bit here and a little bit there, just to go to the next step. That's the goal."

Jim Courier, who works here for Channel Seven, claimed yesterday that Lendl had other goals, saying that he had returned to tennis for "mercenary" reasons. "He hasn't been allowed to make any money from tennis for the past 15 years because he cashed in disability insurance," Courier said.

Lendl's response was typically blunt. "That's ridiculous," he said. "Jim shouldn't be saying stuff like that. First of all it's wrong and he doesn't have the proper information. End of story."