PARIS — Novak Djokovic may have mothballed his party trick of impersonating fellow professionals, but he’d love to mimic the success of ex-French Open winner Thomas Muster, the one-time ironman of tennis.

The fourth seeded Serbian recently hired Gebhard Phil-Gritsch, who helped Austria’s Muster capture the 1995 Roland Garros title - a victory based on an iron will and tip-top physical power.

“My new fitness coach is analysing all the small things, which are really important in the fitness work of the tennis player,” said 22-year-old Djokovic.

“He’s been in tennis for a long time. He’s worked with Muster. So it’s quite important to have somebody who is familiar with the way it works in tennis, and I’m happy.

“We have been working for a month already, and we have had good results. Physically, I feel fit and hopefully can continue the way it is.”

Aside from world number one Rafael Nadal, Djokovic has enjoyed the most impressive claycourt season, winning the title in Belgrade and finishing runner-up to Nadal in Monte Carlo and Rome.

He also had four match points against the great Spaniard in their marathon four-hour semi-final at the Madrid Masters before the reigning French Open champion prevailed.

Despite his improved physical condition, Djokovic isn’t giving away the secrets of his work with Phil-Gritsch.

“You can’t expect me to tell you that. Everybody has his own way,” replied Djokovic, who reached the French Open second round on Tuesday when opponent Nicolas Lapentti of Ecuador quit with an injury in the second set.