Ex-Brazil international Lucio has little doubt Oscar still has a role to play at Chelsea and has backed his compatriot to become a key figure for the Premier League champions again.
The 24-year-old joined Chelsea from Internacional in July 2012 and quickly became an important first-team member at Stamford Bridge.
Nevertheless, Oscar is no longer an undisputed starter under Jose Mourinho this season as he has struggled to find his best form.
Lucio feels it is too soon to write off the gifted midfielder, though, and believes he will soon be back to his best.
"Oscar plays an attacking and skilful game with the national side. At Chelsea, he plays a different role. It is two different styles of play and he needs to adapt," Lucio told IBTimes UK.
"There will be a period where Mourinho's style may not suit him, but he has to adjust and adapt. Once he does it, he will be a top player, a very good player.
"His dip in form is just a question of adapting. He should work hard in order to improve his game and be a big player at Chelsea."
Oscar has netted twice in seven appearances in all competitions for Chelsea in 2015-16.
