Onana joined Everton last summer but has struggled to make his mark this season amidst the team’s struggles under previous manager Frank Lampard.
He has looked better since Dyche took charge of Everton and played important roles in the wins over Arsenal and Leeds United in the last three league games.
Defour, who worked under Dyche at Burnley, is a fan of his countryman and insisted that the young midfielder is a confident young man who has belief in his natural abilities and talent.
However, he stressed that the Premier League can be an unforgiving environment for any player or team who are not improving.
But he is confident that Dyche is the kind of manager who could help Onana to add more to his game and turn him into a real powerhouse midfielder, as long as he is willing to learn and grow.
Defour told the Liverpool Echo: “I’ve spoken to him. He’s confident because he believes in his qualities and he’s worked hard to get where he is.
“He was really open because he knows me and knows he can speak to the gaffer and myself for advice.
“It was a really good conversation, he listened and I think if he carries on developing then he can have a great career.
“The Premier League is unforgiving, we see that with Everton now, they’ve always been one of the top teams but the Premier League never stops improving.
“If Amadou wants to evolve like he’s doing now and Sean can work with him, he can add new elements to his game and become a really good player.
“He has every quality to do the business in the Premier League.
“I saw Sean’s first game as Everton manager against Arsenal and what was a really good Onana.
“I think with his qualities, if he can work with Sean and add what he will demand from him then he can become a real midfield powerhouse.”
The 21-year-old midfielder has been a constant presence in the Everton team this season and has 21 Premier League appearances under his belt.
