Arsenal star Santi Cazorla admits he is clueless as to why compatriot Juan Mata is out of favour at Chelsea under Jose Mourinho, amid speculation the Spaniard is wanted by Manchester United.
Mata has established himself as one of the most complete midfielders in the Premier League during his time in west London but, since Mourinho returned to the club in the summer, the midfielder has been cast aside.
The 25-year-old has started only half of the Blue' games in the league this term following the admission by Mourinho that he would favour Oscar ahead of Mata as his starting No.10.
It is a stance Cazorla finds difficult to fathom and the Gunners midfielder has urged his Spain teammate, who could have moved to the Emirates Stadium in 2011, to seek out his manager for crunch talks.
"If he does not play he will want to leave Chelsea, this is obvious because it is a World Cup year," the Arsenal ace said, according to the Daily Star.
"It's weird because Juan Mata does not play [but] he has proved his worth to Chelsea and to see him on the bench is weird. He should ask Mourinho to know why he does not trust him."
Speculation is intensifying that Manchester United could launch a bid for Mata before the close of the transfer window with the player eager for more regular action ahead of the World Cup this summer.
David Moyes is reported to have been informed the champions will have to meet Mata's release clause of £37 million - which would break their club record - if they hope to bring him to Old Trafford.