Mourinho is happy with the Brazilian's development.
"He's a young guy, he's not a naturally physical young man and he suffers with the accumulation of matches,' said the Portuguese. 'He's a kid, Oscar is the kind of guy where the talent is there all the time but the physical, top condition to express the quality he has is not always there, so we have to take care of him.
"I can imagine him at 25 or 26 years old, we all can, but at the moment it's different, he's a young guy. We understand each other very well and we speak the same language which makes it even easier.
"He's performing well for us; maybe in the last couple of matches he wasn't the same because at the beginning of the season he was the best player in the team. He was the player that was really making a difference in the first three or four months.
"At this moment he's not being a match-winner or scoring goals but he's not playing badly. There are no problems. To play against West Brom away, with the conditions we had, it wasn't the best situation for him to be at the top of his game, but he's a fantastic player. He plays today and hopefully he plays well."
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