Mourinho: I don't know my best back four

After a 3-0 loss to Tottenham, Jose Mourinho accepted he was unsure about Manchester United's best defence.

Manchester United has leaked seven goals from its three matches in the league.   -  Getty Images

Manchester United manager Jose Mourinho admits he is unsure what his best back four is after a tough start to the Premier League season.

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Mourinho is under fire after United suffered a second loss in three league games with its 3-0 defeat to Tottenham at Old Trafford on Monday.

The Portuguese tactician is yet to start the same defence in any two games this campaign, with only left-back Luke Shaw starting all three matches and midfielder Ander Herrera used at centre-back against Spurs.

Asked if he knew what his best defence was, Mourinho accepted he was unsure.

"Why not? Because in the first game [it was Victor] Lindelof and [Eric] Bailly," he said.

"Today played [Phil] Jones and [Chris] Smalling, but now Jones is injured, and next match it will be Smalling, with another one.

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"When Marcos Rojo comes he will be an option, and no, I don't know my best back four."

United will look to bounce back when it visits Burnley on Sunday.