Gael Monfils' brilliant run through to challenge Rafael Nadal in the final of the Qatar Open has underlined he is still perhaps the most talented, and most popular, under-achiever on the ATP World Tour.
The revival of the likeable but enigmatic Guadeloupe-born Swiss-resident Frenchman has once again raised hopes that he might yet conquer the injury and motivational problems which have frustrated his special talents.
Monfils has had knee, back and wrist ailments which not only cost him form and fitness but sapped his morale and motivation. These caused him to fall from his highest ranking of world number seven in 2011 to a spell outside the top 100 last year.
The plunge threatened not only his career but his entire well-being, confounding many excellent judges of tennis, including the legendary Pete Sampras, who believed he has enough ability to reach the later stages of Grand Slam events.
Monfils' four emphatic wins this week - including one over compatriot Richard Gasquet, the defending champion - have revealed him as still one of the tour's fastest movers, possessed also of a great first serve and improving mental abilities. He should climb back to a ranking not far outside the top 20.
However his predicament has been complicated by his having been without a coach for more than a year, which gives him freedom he enjoys but makes great demands of his will-power and self-discipline.
"It's a positive and negative," Monfils admitted. "It makes me do things on my own. It makes me believe in my motivation and believe I can beat top players.
"It's not easy every day to run and go to the gym. It shows I have got more maturity. It is not easy because sometimes I feel lonely and then it is difficult. And there is no-one to give me tips before I play a match."
Monfils' popularity is enhanced by an extrovert personality which produces light-hearted moments off court and showboating moments on it. Some people remember how he amused them at the Qatar Open in 2007 when he lost to Roger Federer in a fine final.
That year he challenged a coach to a crazy sprint race among the vehicles in the stadium car park and distinguished himself with a worryingly flexible limbo dance in which he contorted himself under a very low bar at the player party the night before the final.
Shackling his unique expressiveness would be unwise, but time is nevertheless growing short for the player who won three of the four junior Grand Slam titles and became the ATP Newcomer of the Year soon afterwards. Monfils is now 27.
He is now more aware then anyone of the need for clear purpose and steady discipline and of the size of the challenge in maintaining good mental shape.
Some analysts think he needs a better balance between attack and defence in his game, both of which he has tended to employ in spectacular extremes, and may benefit from a less self-distracting on court persona.
Last year, after Monfils split with coach Patrick Chamagne, French tennis legend Henri Leconte apparently suggested that Monfils was depressed and considering premature retirement.
"Gael is completely lost and doesn't know what to do," he is reported as having said. "When you're hurt so long, you can quickly go into depression. He gives the impression of a wounded animal. But it is the turning point in his life."
Chamagne apparently believed Monfils had been affected by the pressure from a succession of injuries, and allegedly said: "I would not be surprised if it was a return to hell."
Since then Monfils has been bolstered by a win over Federer in Shanghai in October and by his preparation for 2014, conducted in Los Angeles, Paris, and his home near Geneva, which seems to have got him in decent shape.
"I have a couple of high goals in my mind and I will try to manage to do it," he said here on Friday. "But for the year I want to try to be myself and not give up. And to be happy - when you are happy, positive things happen."
However this the fifth time in six years Monfils has reached a semi-final or further in January, and he has never yet capitalised by doing well at the Australian Open.
If this week in Doha has been important for him, the next three weeks may be even more so. What happens in Melbourne could have a profound influence on his future.