Arsenal suffered their first defeat of the season after losing to Bournemouth at the Vitality on match day eight. Mikel Arteta will not be encouraged by what he saw on show on the South Coast, as the Gunners were unable to match the threat of Bournemouth in large spells of the game. Gabriel Martinelli missed a clear chance to score in the second half before Ryan Christie and Justin Kluivert scored to ensure the points remained at the Vitality. Arsenal were simply not good enough on the night however, matters were not made any easier for Arteta’s side as William Saliba was sent off after just 3…