Adding to a capable team is not easy, while the club may not dare to shatter the wage structure for Vinícius Junior After beating MK Dons 3-0 in a training-ground friendly last weekend, Arsenal truly begin their pre-season programme against Girona on Saturday evening. It marks a return to action for the Premier League champions, who will want to show their success last season was not a one-off. Retaining the English title is incredibly difficult if you are not Manchester City. No other club has…