Ally McCoist accused William Saliba of being careless during the first-half between Arsenal and Porto at the Emirates, with the Frenchman’s poor header presenting the visitors with an opportunity to get a shot away. Arsenal may have been a little surprised by how Porto took the game to the Gunners during the early stages of the second-leg. Certainly, Sergio Conceicao’s men seemed to settle into the game much quicker. And Evanilson was one of those to have an attempt in the opening 20 minutes, putting his strike from outside the penalty area just wide. Ally McCoist criticises Arsenal defender W…