Jamie Delgado has claimed that Gilles Muller has the potential to cause big problems for Novak Djokovic when the two players meet in the fourth round of the Australian Open.
Delgado previously served as Muller's doubles partner before becoming his coach, and the Brit believes that a promising performance against the world number one could set the 31-year-old up for a fine season on tour.
"It will be interesting if he can play his game. There's no better test of where you're at," Delgado told BBC Sport.
"I'll be excited, nervous for him and for us, and obviously egging him on and hoping he does himself proud, because he's good enough to give Djokovic trouble.
"If he were to do that, even if he was to come up short it would help a lot for the rest of the year."
Muller beat John Isner in the third round to set up the meeting with Djokovic.