The Benfica ace is one of Europe’s hottest properties right now after a spectacular season in which he scored 15 times and contributed nine assists as his team secured the Primeira Liga for the fifth time in six seasons.
Called up to the senior Portugal squad for the upcoming Nations League finals in June, which take place in his home country, the 19-year-old could line up alongside Cristiano Ronaldo.
And the forward is being rated as the country’s most exciting footballer since Ronaldo’s emergence – though Carvahal believes his qualities reflect a Brazilian, not his compatriot.
“His characteristics are more near Kaka in my opinion, the way he drives the ball, connects play and his goals,” Carvalhal, who also managed Swansea, told BBC Sport.
“Bernardo Silva is one of the best players in the world at this moment. 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."
Felix, who signed a new contract last November with a release clause of £106m ($135m), has understandably attracted the interest of Europe’s elite club, and it is thought both Manchester City and United are favourites to prise him away from Benfica.
The interest isn’t a shock to Carvalhal. He added: "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 No.9 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.
"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."