Andy Murray makes 'no guarantees' over his language at the Australian Open after cursing is picked up by microphones in Brisbane You have been warned: The courts will not be the only things that are blue when it comes to Andy Murray's Australian Open matches. The world No 3 has found himself at the centre of whether his language on the court is suitable for a family audience after his cursing was picked up by microphones at the Brisbane International tournament yesterday. And despite promising to watch his Ps and Qs recently, he brushed off any pledge to wash his mouth out with soap if any industrial language gets picked up on court at the rod Laver Arena. Murray, who beat Uzbekistan's Denis Istomin to book himself a place in tomorrow morning's Brisbane International semi-final against Kei Nishikori, is known for wearing his heart on his sleeve - particularly when things are not going to plan in a match. But when asked whether he will attempt to tone down his language in Melbourne, he said: "I don't really know how that will go, to be honest. A lot of times I get asked after matches about it. It can get picked up on the microphone or whatever. No-one has mentioned anything to me (in Brisbane) yet but the microphones at the Aussie Open are all around the court, so we'll see. Last month the US Open and Olympic champion said he would try and curb his cursing: ""Obviously, me saying "s***" or whatever is bad and wrong, and it's something I want to try to stop doing." But his tone was far less conciliatory after his win over Istomin - and he said other players are a lot worse when it comes to swearing like sailors while in the heat of a match, but they are not chastised for their utterances because they let fly in other languages. "Where it (the pledge to stop swearing) came from was when I got asked a question," he said. I was doing an interview over the phone. I got asked about swearing on the court. I said "obviously I don't mean to do it. I don't want to do it. Sometimes you get frustrated and you do and obviously I will try to stop. I didn't make any promises or guarantees that I was going to. Then it came out that I've said this year I will stop swearing. What I also said was that a lot of players swear on the court and a lot of people say a lot worse things than me - in other languages. It doesn't get picked up the same. So where I would obviously love to stop doing it, I try not to. But I can't guarantee it. Meanwhile Roger Federer, the world No 2, is confident his lack of match time will leave him "refreshed" leading up to the Australian Open. Federer has not played competitively since November but he said: "I am very happy that the year is starting. It's a bit of a different preparation for the Australian Open this year but I'm confident I am mentally refreshed, which I am, and physically I am fine and that I will play a good Australian Open.