Jose Mourinho lauded Oscar's contribution as Chelsea beat Crystal Palace on Saturday to consolidate their place at the top of the Premier League.
The Brazil forward struck a sublime free-kick after six minutes to put Chelsea on their way to a seventh win from eight games this season in a feisty 2-1 London derby victory at Selhurst Park.
Oscar's fine form last season and his selfless displays convinced Mourinho to play him ahead of Juan Mata, who left for Manchester United in January.
The 23-year-old's form tailed off as Chelsea's title challenge faltered, while it was suggested he was preserving himself for the summer's World Cup finals in Brazil.
Mourinho does not regard Oscar as simply a playmaker, as the Brazilian continues to flourish.
"Oscar, in this moment, is not a number 10," the Blues boss said.
"He had an evolution, a mental, tactical evolution that allows him to be a fantastic player.
"Can he physically improve? Of course. People forget that he is still so young."
When Cesc Fabregas, who scored Chelsea's second, was the subject of close attention against Palace, it was Oscar who dropped deep to fill the Spaniard's role.
Mourinho added: "He's not a number 10 that plays with the ball at his feet, he's a number 10 that looks back, looks to the side, analyses the game and sees where the team needs him to move to get the ball and also to create balance.
"In the first half when they had (James) McArthur playing man to man with Fabregas, I was so happy with that.
"Fabregas was taking McArthur from the central area and Oscar was dropping back to play.
"And Oscar and (Nemanja) Matic controlled the game completely for us."
Palace responded with a late Fraizer Campbell goal, which proved merely a consolation, but was set up by Wilfried Zaha, who helped the Eagles to promotion in 2013 after signing for Manchester United.
Zaha has had limited opportunities to impress back on loan at Selhurst Park, with Palace boss Neil Warnock determined for the winger to improve his decision making.
Warnock said: "Wilfried has been working very hard with me for the past 10 days.
"He knows what I think about him and what I am going to do with him. He's clear about that.
"His discipline is a lot better. His attitude is super for me."