Spare a thought for Gerard Tsobanian, a member of that band collectively labelled as tennis agents who rarely engender compassion. In modern times the two players who have habitually shown a cavalier attitude, failed to fulfil their potential, smashed more rackets, been hit with most fines and generally caused abject frustration among their entourage are Goran Ivanisevic and Marat Safin. Tsobanian manages the affairs of both.

Ask him which of the pair have caused him the most torment and aggravation over the years, Tsobanian replies: “I’m not going to tell you.” Then with a wink of the eye he adds the riposte, “I’ll say this, however. It wasn’t Goran.” Safin is the unquestioned maverick of the modern game. Undeniably brilliant, he possesses such abundance of natural talent to make the current trinity at the top of the men’s game of Roger Federer, Rafael Nadal and Novak Djokovic move over a little and make room for a fourth person on their sofa perched at the pinnacle of the game.

So far, from a 10-year career that initially promised so much that the late Mark McCormack - patriarch to all tennis money-men - used to sit courtside taking snapshots of the young Russian imagining what riches could be realised, Safin has amassed more than $13m in prize money and won two Grand Slam titles. Asatisfactory haul, it would have to be said, but even the most conservative estimate would agree somebody with such sublime skills should have at least tripled that collection in terms of cash and trophies.

Probably the top-ranked player who has got closest to understanding the inner psyche of Safin was his compatriot and Davis Cup teammate Yevgeny Kafelnikov, who was nowhere near as naturally gifted but infinitely more workmanlike in terms of workrate and tournaments played during his career. “Marat is so talented, he will be as good as he wants to be,” insisted the former French and Australian Open champion. The problem has been commitment and Safin holds his hand up. “I’m not disciplined enough,” he says. “I get bored too easily.”

The most precious memories of Safin’s career have been awe-inspiring performances on the court and unforgettable examples of his playboy image off it bracketed together. In 2000, at the age of just 20, he took the breath away from the collective tennis world with a straight sets annihilation of Pete Sampras in the US Open final that still stands as one of the most emphatic big-match victories in the history of Flushing Meadows. Less than an hour later, as he set about explaining his feelings of elation to the world’s press, the doors of the interview room were flung open and in walked several waitresses pushing trolleys laden with iced vodka, caviar and lobster. Celebrations have rarely been so impressive.

Then there was the night in Melbourne in 2002 when he battled through to the Australian Open final by beating Tommy Haas in five sets, the last couple being so emphatic that he dropped just two games. In Safin’s support group were a trio of stunning blonde beauties who wandered off with him into the darkness afterwards. In hind-sight it shouldn’t have come as too much of a surprise that Safin came up horrendously short in the final two days later against unlikely champion Thomas Johansson.

Safin did make amends by winning the Australian Open title three years later, in the final destroying the host nation’s hopes of Lleyton Hewitt raising the trophy. The destruction of Federer in the semi-final was a performance of such power and perfection it eclipsed the win over Sampras in New York. But one of Safin’s most prized recollections of the tournament was the eye contact he made with Olivia Newton-John as she was introduced to the two finalists on court after entertaining the Rod Laver Arena crowd as a curtain raiser.

Then there was the occasion at the French Open when he was so delighted at reaching a seemingly irretrievable drop shot against Felix Mantilla and turning it into a stunning winner that it occurred to him that the best form of celebration was to lower his shorts.

“It was a great point for me,” Safin explained. “I felt like pulling my pants down. What’s bad about that?” The umpire thought it was bad and gave Safin a point penalty for the episode.

Characteristically he reacted with anger: “All the people who run the sport, they have no clue,” said Safin. “It’s a pity that tennis is really going down the drain. They do everything that is possible just to take away the entertainment.”

Yet for all the good times there have been numerous moments of dejection. Injuries have been a constant problem for the 6ft 4in giant, to the extent he maintains every other year has seen a crisis of some sort.

His year-ending world ranking is like a rollercoaster, No 3 one year, No 77 the next, before battling back to No 4. In the autumn of 2006 he fell out of the top 100 altogether and flirted with the same fate again just a couple of months ago. Currently he is rated the world’s 75th best player, which is a travesty given his capabilities, although victory in the next round against Switzer-land’s 13th seed Stanislas Wawrinka will substantially improve his place in the men’s singles standing.

Many men have been recruited to coach Safin over the years before walking away from the highly paid appointment, frustrated at the inability to sufficiently motivate their employer. Mats Wilander once famously grew so dejected with his task that the seven-time Grand Slam champion simply instructed his charge to throw his rackets into the centre of the back fence rather than at the supporting posts. That way they were not so dangerous to those who shared the court.

Tony Pickard, the coach who cajoled Stefan Edberg to two Wimbledon titles, was one who tried. Eight years ago he was appointed on a temporary basis by Safin’s mentor Ion Tiriac to educate the youngster, brought up almost exclusively on clay, on the vagaries of grass-court play. Yet it was an arduous task, so alien was Safin to the concept of the low bounce and the skidding ball.

Pickard, very much an English tennis sage these days, grinned reflectively as a host of shocked spectators darted away from Centre Court in search of a cup of tea, or perhaps something stronger, after many people’s tip for the title, Djokovic, was summarily shoved out of the tournament in straight sets by that former pupil.

“He always said he couldn’t play on grass because he didn’t trust the stuff, but the potential was always there,” said Pickard. “He’s probably the most gifted player in recent years who has never got to a final here. But every once in a while the young man shows us what he’s capable of doing.”

Such has been the case at this year’s Wimbledon, and two more victories, against Wawrinka and then either 10th-seeded Marcos Baghdatis or Spain’s Feliciano Lopez, will put Safin beyond the quarter-finals for the first time in a barren 18-month spell and possibly in for another tussle with Federer, who clearly regards the Muscovite as the most potentially dangerous player left in the top half of the draw.