Charlie Nicholas is back with his Premier League predictions – but who is he tipping on matchday seven? Manchester United and Arsenal meet in a hotly-anticipated Monday Night Football clash at Old Trafford to conclude the round of fixtures.Premier League fixturesPremier League tableHow to watch free PL highlights Who is Charlie backing to prevail on Monday? Manchester United vs Arsenal – Monday, 8pm, live on Sky Sports Premier LeagueI am laughing already because we have a tale of two bad defences. Man United have one of the best keepers in the world in David de Gea and the most expensive defender in the world in £80m Harry Maguire. They got picked apart against West Ham and were nowhere near to earning anything from the match. Arsenal have five captains supposedly! Let the games begin!Hector Bellerin played a little bit against Nottingham Forest. Ainsley Maitland-Niles is suspended and though Unai Emery has been cautious about him, I think Bellerin should play. Kieran Tierney should be in, but Rob Holding will miss out I think. Arsenal will play two protectors – to my amazement, Granit Xhaka will still be in, but I would go with Lucas Torreira and Matteo Guendouzi. I would…