In the absence of the injured Roger Federer -- last seen taking the mountain air in Switzerland -- Juan Martin Del Potro might just be the most adored man in tennis.
Though after all the affection and euphoria that Del Potro's comeback appearances have been generating across three continents of late, in Europe, South America and then North America, he is possibly about to reach the limit of his global appeal with a long weekend in Glasgow, the city of Andy Murray's birth.
Think of the Davis Cup semifinal between Britain and Argentina, which begins on Friday at the Emirates Arena, as the ultimate test of Del Potro's new gilded status. It has often been said that you can put Federer on any court in the world, even against a local in a Davis Cup rubber, and the crowd can't bring themselves to turn on him, and perhaps 'Delpo', as he is known, is now in that category.
Consider the noise, emotion and "craziness" in New York when he defeated Steve Johnson in the second round of the US Open -- it's not often that someone is treated so warmly when playing, and beating, an American in America. How will it play out when he faces a Scottish opponent in Scotland, before an audience which is a good two, three times more vocal than the spectators on Wimbledon's Centre Court? Perhaps, like Federer, Del Potro's appeal really will transcend the tribalism of the Davis Cup.
Though let's not be so foolish as to imagine that Del Potro -- a former US Open champion, and the silver medallist at the Rio Olympics -- should be expecting a Glaswegian love-in. Or a repeat of what happened in New York during his US Open quarterfinal defeat to eventual champion Stan Wawrinka when the galleries gave him a standing ovation and sung "Ole, ole, ole, Delpo, Delpo".
Seven years after hitting through Federer to win the 2009 US Open title, Del Potro has had another summer of euphoria. Despite his modest position in the world rankings of No. 64 as he pulls himself up the standings again -- and that's a distinct improvement on his pre-US Open status when that was a triple-digit number -- Del Potro would currently be on the top line of any worldwide popularity chart.
So above even Murray, the Wimbledon and Olympic champion, with the pair expected to play singles on Friday, in what will be a rematch of the gold-medal match in Rio. Del Potro hasn't played a singles rubber in the Davis Cup for four years, though that should hardly have a bearing on the indoor hard court in Scotland. Of far greater relevance is how he has been performing at such a high level of late, including tormenting Murray in Brazil.
"It's going to be interesting, I think. All of the British guys are playing well, and they are the favourites to win, but this is the Davis Cup so anything can happen," Del Potro has said.
Del Potro's re-emergence as a force at the top of the game -- after missing so many years to wrist operations, and coming so close to quitting -- is one reason for his surging popularity. Another is his emotional nature. There isn't a more open and emotional man in tennis; it's been a rarity this summer to see him without pink eyes and his head buried in a towel.
Recall his reaction at Wimbledon, at what was his first Grand Slam for more than two years, when he defeated Wawrinka in the second round -- as he put it, it was a victory that made him feel alive again. Listening to comments like that, no wonder the tennis public have fallen for him,and fallen hard.
That connection between Del Potro and his global followers was only strengthened by his Olympic-standard hitting and Olympic-standard emoting and hugging in Brazil, with his first-round victory over Novak Djokovic possibly the most emotional contest of any sport at the Games with both winner and loser weeping as they left the court. More tears followed when he defeated Rafael Nadal in the semifinal and again after losing a four-setter to Murray. The Olympics brought some of the happiest times of his life, he has said.
And the US Open wasn't bad either, with the singing and chanting during his match against Wawrinka moving him to tears. 'Beloved', people said, and that wasn't over-selling him.
Del Potro has the power and danger in his arm to blast a hole in Murray's and Britain's Davis Cup ambitions. And yet, for all that, Glasgow might still reveal a fondness for the man.