Chelsea boss Jose Mourinho has admitted Oscar's form has tailed off in the second half of the season after an impressive start.
The Brazilian started the season well and his form played a role in Juan Mata's Stamford Bridge exit, but Mourinho has told Sky Sports he's been disappointed with Oscar since the turn of the year.
He said: "I think he was our best player for months, from August to November or December. He was absolutely fantastic. And after that he was up and down.
"He arrived in the crucial moment of the season in a down. Injuries, couldn't train, was trying to arrive to the game but didn't, was a doubt for the game, the game was too big to play with a doubtful player, so he arrived in the crucial moment of the season in a low."
The 22-year-old hasn't featured for Mourinho since the 2-1 defeat to Sunderland in April - a game in which he was hauled off after an hour with the score at 1-1.
The comments from Mourinho come just days after he criticised winger Eden Hazard for not being a team player.
The apparent disharmony at Stamford Bridge may come as a surprise to some as a season of promise comes to an end.
The Blues came close to another Champions League final but were knocked out at the semi final stage while a win today against Norwich could see them go top of the Premier League with just one game left.
One of the stand out performers for the club this season has been another Brazilian - Willian. And Mourinho was keen to use him as an example of what can be achieved with hard work.
He said: "Willian has improved. But you can't succeed with everybody. At the end of the day, it's up to them. You try to help, but it's up to them.
"You can help to build them. I'm not saying I'm going to succeed withevery one of them. But, for example, I have Dr Biosca, who was the doctor in Shakhtar Donetsk for many years with Willian, and he says he doesn't recognise Willian: the professional, the player, the commitment, the ambition.
"The only thing he recognises is the talent because he has improved. You can't succeed with everybody. You try to help but it's up to them. Every one who is in an age of improvement needs to improve."
Both Oscar and Willian will be in the Brazil squad for this summer's World Cup in their homeland, and when asked if the former was already looking ahead to the showcase event Mourinho said: "There are things you can't resolve."
Despite his inconsistent end to the season, the playmaker has amassed 46 appearances in all competitions, netting 11 times in the process.