Mikel Arteta has said Ruben Amorim has already put his "fingerprints" on Manchester United but warned of the unpredictability of management as he tries to restore the club to former glories.

Of course Manchester United were going to lose. They didn't have the players. They didn't have the time drilling a new system. Most of all, they didn't have the most intimidating weapon in the arsenal of any Premier League side,

Arsenal manager Mikel Arteta has warned Manchester United counterpart Ruben Amorim of the "unpredictable" nature of life at the helm of one of England's top clubs as the pair prepare to do battle on Wednesday.