Now 38, Italy international and Udinese captain Antonio Di Natale played with Alexis Sanchez between 2008 and 2011.

The seventh-highest scorer in Italian football history (behind the likes of Silvio Piola, Alessandro Del Piero, Giuseppe Meazza, Roberto Baggio, Filippo Inzaghi and Francesco Totti), Di Natale knows just what it takes to make for a good strike partner, and he rates his former Chilean foil as the best he has played with.

In 2009, the duo teamed up with Simone Pepe to establish one of the most potent attacking threesomes in recent Serie A history, scoring 41 goals between them and forging an almost telepathic understanding.

What had you heard about Alexis Sanchez before he came to Udinese?

"I’ve played with a lot of champions, but he is the best; and he’s proven it by performing for enormous clubs such as Barcelona and Arsenal" Antonio Di Natale

I knew that Udinese had bought a good youngster from Chile who was supposed to be a real talent. I knew also he was called “Nino Maravilla”. Now in South America they are pretty generous with their nicknames, and, here in Udine we’re used to hearing these kind of things, talk of the next big thing breaking into our squad: after all, the strategy of the club is to pick out, follow, analyse and then eventually buy youngsters that are almost unknown and still outside the radars of bigger teams.

Alexis was bought from Cobreloa and then loaned to Colo Colo and later to River Plate: he made the ‘jump’ to a bigger team (Colo Colo) and a different and more competitive league (Argentina) in his stride.

So we knew he was a star in the making and that, even though he was very young (Sanchez was 18 years old when he eventually came to Udine), Alexis he had shown that he could live up to his potential.

Can you tell us your first impression when you saw him training?

I was amazed by his technical skills: he did things with the ball that were more typical of a juggler than a footballer. But what really impressed me was the approach he had to the everyday work.

In my career, I’ve seen a lot of talented players squandering their abilities with the wrong attitude, with a sort of indolence. Alexis was the contrary: I’ve never seen him distracted, he was always attentive and focused, he was always ready to work harder in order to improve, to add some new trick to his natural talent.

He was also interested in those aspects of the game that talented forwards often hate: the tactical aspects, the physical dimension, the way to help the midfielders and even the full-backs. This is probably his secret, and the thing that has allowed him to become one of the greatest players around today: he combines individual quality with a willingness for collective sacrifice.

You’ve played with a lot of talented forwards in your career, both at Udinese and with the Azzurri…

Stop: I know what you are going to ask. And the answer is: ‘Yes he’s the best partner I had in my life’. Like you say, I’ve played with a lot of champions, but he is the best; and he’s proven it by performing for enormous clubs such as Barcelona and Arsenal. It’s quite easy to be a star in a little or medium team, where there is no pressure and where competition is far to be ferocious. But to confirm your individual qualities within the biggest teams is something only few can achieve.

Does he still have room to improve?

"I’ve never seen him distracted, he was always attentive and focused, he was always ready to work harder in order to improve" Antonio Di Natale

Alexis is able to do everything, he’s one of the most complete attackers in the world: he could play as a winger, as a striker, as an inside forward. At Udinese, there were even emergencies where he filled in as a midfielder! But that’s not to say he can’t get better.

When a player thinks he has no need to improve, he’s close to the end, he’s destined to be dethroned. Sanchez, on the contrary, has always shown a hunger to get better, and he’s always been willing to sacrifice the sweat and tears to do so. I never got the sense that he was satisfied with what he achieved.

This lack of complacency has helped him to become the star he is, and it is what will help him remain on the top for many years. It’s hard to say exactly where he can improve. Like me, he’s not a giant: maybe there is scope for him to become a better header of the ball. Maybe…

Have you been following his progress at Arsenal?

I always try to watch Arsenal games, just as I used to watch the Barcelona matches when he was there. One thing you know with Alexis is that he’ll always put on a good show. We met up in Watford this summer, and I had the chance to catch up with him.

Although he is now a truly international star he hasn’t changed; there’s not a drop of arrogance in his attitude. He’s the same old boy he was in Udine. For me, this is maybe more significant and admirable than his trajectory as a player.

Have you got any anecdotes that reveal what he is like as a person?

"Although he is now a truly international star he hasn’t changed; there’s not a drop of arrogance in his attitude" Antonio Di Natale

He’s a man who places a big importance on friendship. When I met him in Watford, I asked him for an Arsenal shirt because my son Filippo is a huge fan and I had promised him to come back from England with a present.

You know what he did? He simply picked up the shirt he had been wearing a few hours earlier in his first match for Arsenal (Arsenal v Benfica in the Emirates Cup) and gave it to me. He could have saved it as a souvenir, but he preferred to give a present to my son.

Recently Alexis came up against Neymar at the Emirates. How would you compare the two?

They’re both wonderful players, who play talismanic roles for top club sides. When you’re talking about players at that level, it’s always difficult to say who’s better. If I was a coach, I’d love to have both of them in my team. But if I had to choose one, I’d choose Alexis: because he’s a little more ‘concrete’ than the Brazilian.