Arsenal could already have the next Kobbie Mainoo on their hands, but they will have to change their plan for one academy star. Kobbie Mainoo has enjoyed a rapid rise recently. The Manchester United midfielder is still just 19-years-old but has now established himself in the England starting XI at Euro 2024, alongside Arsenal star Declan Rice. Certainly in the Three Lions’ semi-final triumph over the Netherlands on Wednesday night, the teenager was able to outshine Rice. The Arsenal man was far from his best, as he was guilty of losing possession in the build up to Xavi Simons’ goal for the Du…