The tennis star feels that his Argentina compatriot is the finest player in world football and revealed they regularly keep in contact during their respective tournaments
The former US Open champions feels his compatriot has the edge over his Barcelona team-mates as well as the Real Madrid and Manchester United attackers, although he admits he is amazed by the abilities of the world's leading players.
“Messi, he’s got an edge over the rest,” Del Potro told FIFA.com.
“A lot of people say Cristiano is just a level below [Messi] but I’m surprised by what Andres Iniesta, Xavi and Wayne Rooney can do.
“They’re real stars. I’m not saying Cristiano isn’t better than them but they’re right up there too. Bayern Munich have got a lot of great players too and they’ve won the Champions League and the German League with a massive points difference. Right now, though, Leo is ahead of that group.”
The world no. 7 also revealed that he regularly talks with the four-time Ballon d’Or winner, but admits that their commitment to their respective sports make it difficult to catch up as much as they would like.
The 24-year-old said: “We chat from time to time and send each other messages. He likes tennis and I know he watches my games. I congratulated him when he became a father.
“I’d love to see more of him but we just don’t have the time. I have a lot of admiration for him.”