Kaka feels Brazil's World Cup hopes hinge on the form of Chelsea midfielder Oscar.
AC Milan midfielder Kaka, who could have been in the squad himself but for Oscar, claims he is sacrificing his normal attacking game to allow others to shine.
He said: "Many questioned Oscar before the World Cup. But I think he's a great player. For me he is fundamental to this team and must stay.
"Oscar adds a lot to the team in terms of positioning, tactical balance, defence. He is sacrificing his normal game for Brazil. It's obvious.
"There is a lot of pressure on him but he's already shown he deserves to be in the team with his performances. He doesn't just do his job, he helps others too."
He added: "Comparisons between Oscar and me? He has some similarities. He always looks to score and to support the team. I wish him all the best."
