Three weeks after the sacking of Unai Emery, Arsenal have finally named their replacement, with former midfielder Mikel Arteta taking the top job at the Emirates.Emery’s time in charge of the Gunners is not one that will be fondly remembered. It was always going to be a tough job for whoever took over from Arsene Wenger after such a long and successful spell, and it proved to be so for the Spaniard.In his first season in charge, poor late season form meant they missed out on a spot in the top four, despite the teams around them also struggling. They also missed out on qualification through the Europa League, as they were beaten 4-1 by Chelsea in the final.The poor form continued into this season, and when Emery was relieved of his duties at the end of November, Arsenal were eight points off the Champions League places, and had gone seven games without a victory. The man Arsenal have turned to is one of their former players, Arteta, who has been the assistant to Pep Guardiola since he arrived at Manchester City in 2017. It is no doubt a bit of a risk for the Gunners, to put their trust in someone who has no managerial experience. Got 11 minutes free? You're going to love this 📺Watch @m8arteta's first interview on Arsenal Player and the Arsenal App 👇— Arsenal (@Arsenal) December 20, 2019He will have to make changes at the Emirates though. This current squad simply isn’t good enough, and either when it comes to desire, or quality.With that in mind, here are five players Arteta must sell as Arsenal manager, either in January, or in the summer. #1 Sead KolasinacKolasinac doesn't have the defensive abilities that Arsenal need at left-backThis is certainly one transfer that Arteta should look to get done in the summer, rather than January. The left-back area has been a constant problem for Arsenal this season, with Kieran Tierney, who is without a doubt the best player in the position at the club, missing with injury, and he is now likely to be out until March.However, in his absence, Kolasinac really hasn’t been up to the challenge. He doesn’t read the game well enough at left-back, is often caught out of position, and that has cost him when he has come up against some of the league’s better wingers this season. He will be needed as cover for the rest of the current season, but when the summer transfer window comes, Arteta needs to get rid of him.