Murray enjoyed his finest clay-court in the spring – reaching the French Open semi-finals after two tournament wins on the surface – and Muller, who trained with Murray as a junior in Barcelona, is full of praise for the former US Open and Wimbledon champion.
“Back then I knew he was very talented, but, seeing him now, you can see how hard he worked to get there,” Muller said.
“He’s a good example for being in great shape; it helps him win a lot of very tough matches. His dedication and his passion for the game is really big, because there are not many guys that work as hard as him.
“He’s back to where he was when he was winning grand slams, so he can do that again.”
Jamie Delgado, Murray’s close friend, will be in the opposing box to the top seed on Friday in his role as Muller’s coach having played a critical role in reviving the 32-year-old’s career after a two-year elbow problem.
“Obviously Jamie can give me some tips, but everyone knows Andy is a great player,” added Muller.
“It’s going to be a very tough match for me, but also a very good test. It’s those challenges that you want, to play on big courts against the best in the world.”
Murray admits he would like his new coaching team of Amelie Mauresmo and Jonas Bjorkman to last “for a long time”, insisting he does not always need passionate court-side encouragement from his staff.
“I think all players would want to see their coaches looking confident, but concentrated on the match as well,” he said.
“It’s not always about fist-pumping and bluffing, in a way.
“Ivan (Lendl, former coach) barely said a word during matches, which obviously in certain situations is fantastic and you want your coach to be calm.
“But then sometimes in a smaller event if you’re also a bit flat yourself and you need some geeing up or need to be pumped up a bit by your team…
“My physical trainer Matt Little is very vocal and he’s normally the one that leads that side of things anyway.”