Robertson Liverpool chose the No.26 shirt because his son was born on the 26th. According to official website, Robertson replied to the fans' questions, "It is meaningless to choose the No.26 jersey. There was only number 26 left when we went to Dundee United. Coincidentally, my son was born on the 26th, which means a lot to me. " So Robertson Liverpool chose the No.26 shirt because his son was born on the 26th.