Antonio Conte has highlighted the importance of Oscar and feels the Brazilian's defensive contribution in midfield is crucial to Chelsea.
The 25-year-old endured a difficult 2015-16 campaign as he made just 20 Premier League starts and was regularly criticised by the club's fans.
However, he has been a key figure under Conte this term, starting all four league fixtures.
"I always thought this team needed to find a good balance when you have possession of the ball and when you do not have possession and last season Chelsea conceded 55 goals," Conte told reporters.
"Oscar is a good player with great technique and can do both phases, offensive and defensive.
"Now I ask him to always stay focused in the game because he is an important player for Chelsea. He is a good passer and he can score goals. He is in my plan and in Chelsea's plan."
Oscar himself, meanwhile, is loving life under Conte so far and is feeling stronger than ever.
"I feel very fit, physically as strong as ever and I have done a lot of running in the games, have won my duels and am showing my strength," he said.