Former Arsenal star, Charlie Nicholas, has urged the club’s manager, Unai Emery to sign four new defenders this summer’s transfer window. He also wants the former Paris Saint-Germain boss to sell playmaker, Mesut Ozil and defender, Shkodran Mustafi this summer. “We need a whole new backline,” Nicholas told Sky Sports. “I am disappointed that Petr Cech is retiring. I would have encouraged them to give him another year. “Bernd Leno has got mistakes in him and would have benefited from Cech giving him a helping hand. “We are looking for four defenders, so on top of the crazy situation of letting Aaron Ramsey go for nothing, it is not great. “They need two centre-backs and two full-backs. Hector Bellerin will come back and play right-back, as Ainsley Maitland-Niles could be pushed on potentially. Sokratis and Sead Kolasinac are good to have as squad players. “Nacho Monreal and Laurent Koscielny are getting on a bit now. Shkodran Mustafi must be released in my opinion. “Konstantinos Mavropanos and Rob Holding are still to come back when they are fit”. Nicholas added, “Ozil is on £200,000 a week, but where will he move to? If he won’t play then Ozil won’t stay. He has got too big of a personality to stay and be on the bench. “If Arsenal can get him out with a transfer fee then I would. I would give the youngsters a couple more games next year and bring Reiss Nelson back, while looking at a big midfielder too.”