I'm not entirely convinced by Trippier either. He's a bit slow and struggles at times against quick wingers and when there is quick combination play going on around him. He has, however, put in good performances in big games recently.
Right back is the position where we are the weakest, in my opinion. We should look for someone better to bring in this summer. I'm not convinced Aurier will improve. He has some very basic flaws in his game.
I just don't see us writing Aurier off yet given we only signed him on 31st August. So unless we sell Trippier (who I personally dont think is good enough), I can't see how we'll be signing a RB this summer