The comparison is not new, but it was the best shot that Andy Murray could pull off following his defeat by Roger Federer at Wimbledon on Friday.
"People love the way Lionel Messi plays football," said Murray. "He makes it look easy. Roger's like that."
Easy, but genius.
Messi at times looks as if he came out of the womb with a ball attached to his left foot, and Federer with a racket extension to his right arm.
Messi can look serene while dancing between the tacklers on a football pitch; Federer is so calm, so concentrated on the green grass of Wimbledon.
The tennis player and the footballer share a quiet intensity. Their concentration is centred on the ball... They do things that others do only in their imagination.
The difference, of course, is that one is a team player while the other is singularly on his own.
The analogy between Federer and Messi was put onto film 18 months ago when Gillette paired the two of them in a shaving advert. No doubt for a few millions more to the accounts of men who have everything, the ad depicted Messi on centre court, and Federer in the soccer stadium.
Messi striving to win Wimbledon, where today Federer tries for an unprecedented eighth title. Federer in goal, using his long reach to try to keep out a Messi shot.
That's just a commercial. It is a fantasy that we all can dream.
The real thing has even more comparisons than the film makers can pretend.
There's money for a start. Federer has already won more than US$91 million (S$123 million) in a career that began with the winning of the Wimbledon junior title in 1998. That is prize money, excluding advertising contracts.
Forbes magazine has a stab at listing the earnings of Messi at US$74 million this year (US$51.8 million in salary, US$22 million in endorsements). And Federer at US$67 million (US$9 million on court, US$58 million off it).
There is informed guesswork in the figures; none in the values that both bring to their games.
To my eyes, Messi and Federer have a sense of serenity when performing at their absolute peak.
They each exude a sense of pleasure in mastering opponents who want to hurt them with physical blows. Federer is using a racket with a larger head these days, but the service action is from his momentum, his timing.
Against Murray, one of the most accomplished returners of service in the sport, the Swiss master served nine aces in his first three games - and 20 in total in his straight-sets victory.
Murray tried everything he knows, switching his stance, but Roger simply served to the opposite side, with speed around 193 kmh and angles nobody - except maybe Novak Djokovic - would get near.
Federer achieved 76 per cent first serves, even higher than that on critical points. Murray could not break him, and only once in the tournament so far has anyone achieved a single break against the Federer service.
This is vital because, turning 34 on Aug 8, Federer might not be a player to go five sets against the world's best any longer.
But it isn't just the service. Federer was audacious in going for his shots, in running around Murray's comparatively tame second serve to pass the Scot with immaculate judgement, to go for the lines.
When he is in the groove like this, the experts agree that Federer is the best there has ever been. Not one of the best, THE best.
Before Friday's match, when the majority of former champions were lining up to forecast a Djokovic vs Murray final, Rod Laver, the king of the courts 40 years ago, begged to differ.
He tipped Federer based on what he knows, and what he has seen this Wimbledon.
Another expert from the past, Stefan Edberg, the winner of Wimbledon 25 years ago, is working with Federer to try to help the world No. 2 recapture the title that the Fed has won seven times so far.
"I'm not a person who looks in the past too much," said Edberg, now 49. "You can learn from the past, but I'm looking to the future. Roger loves tennis, still has the motivation. He's found a new way of improving his game, with a new racket in his hands."
When Federer was pushed to admit he has a rivalry with Djokovic, he responded on Friday: "The rivalry is really not that important to me. It's only to have that feeling of victory at Wimbledon, and on grass. It's why I still play tennis."
Over the past year, in which Messi has won everything at club level with Barcelona, but failed to win the World Cup and the Copa America finals with Argentina, the essential difference has been obvious.
The Barca Messi had playmates like Andres Iniesta and Xavi Hernandez who shared his creativity, and to a degree served him. Argentina rely on Messi above all else, and opponents know that if they hound the little man, if they tug at his shirt or scythe at his ankles enough, they might isolate him.
Yet the tennis player and the footballer share a quiet intensity. Their concentration is centred on the ball. They do things that others do only in their imagination.
In football, Cristiano Ronaldo is more like Rafael Nadal, a compound of physical size, speed and power. Messi is more like Federer, relying less upon physicality, more upon making the ball do their bidding.
Nadal and Ronaldo beat up their bodies. Every player does to a degree, but there is more subtlety, more nature in the way that Federer and Messi glide around their fields. The freedom to express - to delight - is earned.
As Federer prepares for Wimbledon, Messi is in retreat in Argentina. His Barca triumphs are forgotten because Argentina lost the Copa on penalties.
"Leo was lazy," Messi's grand-dad Antonio Cuccitini said on radio this weekend. "Some of him was there, but the last three games he was bad."
That's one reason, at least, why Federer might be glad to be his own man.