I don't see a problem with this as Mata has played well on the wings in the past. However, the types of wingers Mourinho prefers playing with are more speedy and/or powerful and exertive (ie. Robben, Joe Cole, Eto'o, Pandev, Wright-Phillips, Ronaldo, Di Maria, etc.). Mata is more skillful/technical and should focus on his own qualities perhaps playing on the right side of that attack. I am not sure I agree with the premise that De Bruyne is Chelsea's best set-piece taker and crosser. I think Mata and Lampard are a bit more adept.
In this moment, Oscar is my No. 10 and, if somebody tells me that Oscar is not Chelsea’s best player since the beginning of the season, I’d have to disagree. These are football issues.
[Mata and Oscar can play together], when [Mata] adapts to it. But I’m not ready to play Oscar following full-backs [ed - i.e. as a winger], because he plays in that position for the country with more talented players than anyone else in the world in that position. I want to build with Oscar as my No. 10. I want the other two players, from the side, to adapt to that reality and learn now to do things that they were not ready to do before.
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What are your thoughts fellow Chelsea fans (and maybe even non-Chelsea fans)?
I'm actually happy Oscar has become our number 10. In terms of potential, Oscar could very well be the world's best number 10 in 4 years. And he can't play on the wings. Mata can adapt to the wings though. I'm happy about this decision by Mourinho. But to be honest, I want De Bruyne on the right. He fits the Robben role from 05-06 and is our best set piece taker and crosser.