Jamie Murray says he will not be offering advice to his brother even though he has just beaten Andy's next French Open opponent.
The elder Murray and partner John Peers knocked out Joao Sousa and his partner, Thomaz Belluci, in the first round of the doubles at Roland Garros.
Asked if he would be passing on any tips to Andy, Jamie told BBC Scotland: "He won't listen to me. No chance.
"He's got a good chance as he played him a few times before and always won."
British number one Murray has beaten Sousa in their previous five meetings.
But it is the first time he has faced the Portuguese on clay, the surface on which the Scot has suddenly found a rich vein of form.
"Sousa's a good player, likes playing on clay, although his best results have been on hard courts, he's got a good forehand," said Jamie.
"I'm sure Andy's feeling confident about his chances and I fully expect that, if he puts in a good performance, he'll win.
"He's obviously played really well, he had a great tournament in Munich and he followed that the week after in Madrid, which I guess was unexpected for a lot of people."
Asked if his younger brother could win in Paris, Murray replied: "He is probably in the harder side of the draw I would have thought, but why not?"
Murray and Peers are 11th seeds in France and well placed as they aim to qualify for the end of season World Tour finals in London.
"It was touch and go for a while," Murray said of their 6-7 6-4 6-2 win. "They placed a lot of good tennis.
"We were on the back foot a bit from the start of the match, but slowly but surely we managed to turn it around.
"We have had a lot of good results this year and our ranking has been slowly creeping up.
"We've beaten most of the big teams and we're feeling good about our chances."