ANDY MURRAY has stepped into the ongoing furore over what constitutes legal and illegal on-court coaching at this year's Wimbledon by sensationally revealing that one of his former coaches used to give him hand signals from the box.

The only problem was that the Scot had no idea he was doing it and consequently had no idea how to interpret his gestures.

Boris Becker created a pre-tournament stir at SW19 this year by hinting he may be circumventing ITF guidelines by motioning to Novak Djokovic between points, but the Scot said none of his various coaches on the senior tour had ever employed such tactics and he didn't think he had ever received a coaching warning in a decade on the tour.

Having said that, there was a humorous anecdote which related how he marched off after a futures tournament in Spain to be confronted by veteran coach Pato Alvarez, who was infuriated that the Scot had been apparently ignoring his signals.

"I wouldn't want to speak about other players because I don't know," said Murray, who faces Robin Haase in the Wimbledon second round on Thursday, first up on Court No.1. "But when I was a junior, one of the coaches, Pato [Alvarez], that I used to work with, used to do signals to a lot of his players. I was playing a futures tournament when I was about 16 out in Spain. I won the match but it was a close match, not a very good match. And he went: 'Andy, what are you doing? You never listen to me when you are on the court'.

"I said, 'what do you mean?" recalled the Scot, who practised yesterday with James Ward. "'I was telling you to serve and volley and you weren't doing it'. I was like, 'you never told me what the signals were'. So he was there at the back of the court telling me what to do and I didn't know. But since I have been on the tour none of the coaches I have been with on the tour have ever given me any hand signals or anything like that. Ivan didn't say a word really when I was playing matches and, no, I have not had that since I have been on the tour. I don't think I have ever had a coaching warning, it's possible but I don't think so. For me anyway, it is encouragement I am looking for."

His mum Judy, meanwhile, speaking on what the Met office confirmed was the hottest day ever recorded at the All England Club, said it was time for the rules to be changed in order to protect the players. While it wasn't quite the heat of Melbourne, New York or Dubai, temperatures touched 41 degrees courtside on Tuesday as the world No.3 saw off Mikhail Kukushkin of Kazakhstan. While a 10-minute break between sets two and three is built into matches on the women's tour played in temperatures of 30 degrees and above, there is no uniform rule in operation in men's matches. Judy Murray believes that should change, even if showers are in fact forecast for Thursday which could disrupt Murray's meeting with Haase.

"You cannot mess with people's health," said Judy. "You need to take the advice of doctors and sports scientists as to what that [the rule changes] should be. At what point do you stop a match and at what point do you stop a match from going on? And do you allow them to take breaks to re-hydrate or re-charge or whatever it is?"