Jose Mourinho says Oscar is suffering from fatigue, and winter weather.

The Chelsea manager defended the 22 year old Brazilian midfielder, but offered reasons for a dip in form. The playmaker was pivotal to much of Chelsea’s early season play, but has had a waning influence on their game in recent weeks.

"Maybe in the last couple of matches he was not the same, because in the beginning of the season he was the best player in the team," Mourinho said to Sky News.

"He was the player that was really making the difference in the first three, four months of competition.

"In this moment he's not being a match-winner, he's not scoring goals, but he's not playing bad. Not real problems.

"The talent is there all the time, but the physical top condition to express the quality he has is not always there.

"We have to take care of him. He's a young boy. He's not a natural physically strong man, suffers with the accumulation of matches, suffers with the difficult weather we had."