The Brazilian was named on the bench in both legs of the Blues' Champions League semi-final defeat to Atletico Madrid but was not used by Jose Mourinho and was left out of their victory over Liverpool entirely.
And Oscar has suggested that the injury could keep him out of the clash with Norwich City at Stamford Bridge on May 4, with a place in the Brazil squad at stake.
|11/1||Chelsea are 11/1 with Bet365 to beat Norwich City 4-0|
"I warmed up [against Atletico] but [Jose] Mourinho knew that I could hardly play. Maybe I will not play the next game because I could suffer a more serious injury to my hip and he knows it."
Chelsea are back in the title race after a 2-0 victory at Anfield but Oscar is mindful of missing the chance to represent his country on home soil.
He added: "We're aiming to try and play me in the final clash of the Premier League but I have to take care for the World Cup.
"We still have two very important games in the Premier League because Chelsea can still be champions but it is important I rest because the World Cup is here."