Kai Havertz was heavily involved in Arsenal’s win over Southampton as the German netted his fourth Premier League goal of the season. Mikel Arteta is reaping the benefits of putting full trust in Havertz after a trialling start to life in North London. Despite it taking seven games for the 25-year-old to get off the mark in Arsenal colours last season, the manager never retracted the faith he had in the player. Just over a year down the line and Havertz is at the forefront of all things potent in the Gunners’ attack, adding to his tally against Southampton most recently. READ MORE: Five things…