Benfica star Felix has been linked with a host of Europe’s top clubs this summer.
Express Sport understands the likes of Manchester United, Manchester City and Tottenham have all expressed an interest in the 19-year-old.
But reports suggest Felix is set to sign for Atletico for a fee of around £100million.
Simao, who had spells as a player at both Benfica and Atletico, has warned Felix to expect a different style of football than he is used to under Diego Simeone.
However, when asked if signing for the La Liga side ahead of United and City was the right move, Simao insisted he was confident Felix would be a success at the Wanda Metropolitano.
“Atletico Madrid play different and Simeone likes to play like that, so let’s see,” Simao said.
“It’s a difficult challenge for Joao Felix.
“It’s my favourite team in Spain, Atleti, because I played for four years at Atleti.
“At that time we played just to attack and win like 4-3.
“But now [when] Atletico Madrid play the first thing they think is defence, second the same.
“But if Diego Costa stays in Atletico Madrid, if he plays with Diego Costa, I think Joao Felix will be successful in Atletico Madrid.
“But the first year is not easy for him.”
Simao says Felix is different to a lot of top young players and can see him progressing hugely in the coming years.
“When you look at Joao Felix, Joao Felix is normal, a normal person,” Simao added.
“Not like a young player who starts to play and feels like ‘I’m the best’, when you walk the street ‘I’m the best’.
“Joao Felix is normal, it feels like he’s playing in the street. That’s why he’s a very good player, because he plays like he’s playing in the street.
“That’s why he plays very good and he’s a normal kid.
“That’s why I think in two, three years I think he’s the best striker in Europe.”