Arsenal summer signing Kai Havertz took a long time to settle at the Emirates, but he is now thriving under Mikel Arteta. Havertz arrived to a lot of scepticism after struggling at Chelsea, and continued to falter during the first half of this season. His lack of a defined position meant that he was even trialled as a left-back for the German National Team earlier this season, in what was an ultimately unsuccessful experiment. However, in recent months he has thrived as a centre-forward for Arsenal, with six goals and assists in his last four Premier League appearances. Germany boss Julian Nag…