He has also been called the most exciting Portuguese player since Cristiano Ronaldo.

The 19-year-old forward only made his senior debut for Benfica at the start of the 2018-19 season but scored 15 goals and made nine assists in the Primeira Liga as his club won the title.

He scored a hat-trick against Eintracht Frankfurt in the Europa League in April, becoming the youngest Benfica player and the youngest Portuguese footballer to score three goals in Europe and the youngest player ever to do so in the competition.

His scintillating form earned him a call-up to the senior Portugal squad and unsurprisingly saw him linked to the likes of Manchester United and Manchester City before Atletico swooped, making him the second most expensive teenager behind Paris St-Germain's Kylian Mbappe.

• Atletico Madrid sign Felix for £113m

"Bernardo Silva is one of the best players in the world at this moment," former Swansea boss Carlos Carvalhal told BBC Sport. "But at 19, he did not show the talent that Felix is showing in this moment at 19 - so imagine what kind of player we are talking about."

'It was very clear he was the best talent in the academy'

Felix started his career with Porto's youth team but was released in 2015, reportedly for being "too skinny" and joined their rivals.

He shone at Benfica, and at 16 became their reserve team's youngest ever player when he made his debut in September 2016.

But 2018-19 was his breakthrough season and in November he signed a new deal which included a 120m euro release clause that Atletico were able to activate.

His first-team debut came against Boavista in August and in the next game he scored his first goal against city rivals Sporting Lisbon, with a header in the 86th minute after coming on as a second-half substitute.

His appearances were limited thereafter under former manager Rui Vitoria, but he was an ever-present under new boss Bruno Lage, who took over in January - scoring twice in Lage's first match and ending the season with 20 goals from 43 games in all competitions.

Among teenagers across the top divisions of Europe's leading leagues - England, Italy, Spain, Germany, France, Portugal and the Netherlands - Felix was second in league goals only to Bayer Leverkusen's 19-year-old German midfielder Kai Havertz.

And he is only behind Borussia Dortmund's England winger Jadon Sancho for goal contributions among that group.

"Inside Benfica it was very clear he was the best talent in the academy," said Carvalhal.

"The transition to being a professional is not easy, but to him it was so easy. When you see him off the pitch, talk with him, see him talk in the media, you can see a happy boy. The pressure to win is something he deals with very well."

Jose Delgado, deputy director at Portuguese sports newspaper A Bola, had even higher praise for the youngster.

"Since Ronaldo we have not had a player so exciting and young like him until now," he told BBC Sport.

'Better than Silva at the same age'

Felix will always be compared with Portugal's current players like five-time Ballon d'Or winner Ronaldo and Manchester City's Silva.

But he is often compared to former AC Milan and Brazil forward Kaka.

"They've already called him my heir or the new Kaka," ex-Benfica and Portugal forward Rui Costa has said. "To be honest, Felix is just Felix. He has an extraordinary understanding of the game and the rare ability to know where to be in front of goal."

Carvalhal added: "His characteristics are more near Kaka in my opinion, the way he drives the ball, connects play and his goals.

"Why is he so special? He's a mix between a nine and a 10, he plays like a second striker. He is a good header, even if he is not a massive player physically.

"He knows how to find space well in the last line of defence, that is why he scores a lot and he shoots well with both feet. When he must connect the game between attack and midfield he does so very well. He's a very good technical player.

"What makes him different is he is a number nine when he goes to the last line of defence and he scores goals. But he is also a very good player to connect the game between the lines, to assist and pass."

Speaking in May, before Felix's move to Madrid, Carvalhal added: "That is why we are talking about the big clubs being interested in him. It is not a surprise to me because since the beginning we have been looking at a talented player.

"At 19 he needs to grow up and learn. If he stays at Benfica it would be a good place for him, but if he moves to another club, I hope he will go to a team and manager that understands the football that allows this kind of player to play."

Hopefully for Felix and Portugal, Diego Simeone's Atletico and the Wanda Metropolitano stadium will be that place.