MANCHESTER, England -- Ruben Amorim has launched a staunch defence of his system and insisted Manchester United are not losing games because of his tactical set-up.

Amorim is facing mounting pressure ahead of Sunderland 's visit to Old Trafford on Saturday.

The Portuguese coach has been criticised for sticking with his 3-4-3 formation instead of switching to a back four.

But he is adamant that poor results, including last weekend's 3-1 defeat to Brentford , are not down to the formation.

"If we lost to Arsenal because of the system, it is your job [the media] to make the opinion," Amorim told a news conference on Friday.

"When you look at the game against [Manchester] City, is the first thing you think when the game starts the system? I think you don't think about the system

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