Trent Alexander-Arnold played as a midfielder in his academy/youth career days, but he is currently a RB. Philipp Lahm was a full back before Pep turned him to a midfielder. Andrea Pirlo was a 10 before don Carlo converted him to a 6/dlp, however you understand it. Zanetti was a winger or wide midfielder before becoming a full back. More recently, Matheus Nunes was a shit midfielder before Pep converted him to a Right back. Currently, I can't name 5 RBs that are comfortably better than him. Fede Valverde, you won't be the first, neither will you be the last, accept RB role permanently, help your career, help Real Madrid better and give Real Madrid fans peace of mind.