How could Liverpool replace Alexander-Arnold?

[BBC]Trent Alexander-Arnold's Liverpool departure has finally been confirmed and the Premier League champions will already be thinking about how they could replace him.The 26-year-old right-back has won it all since making his debut in 2016, including the Premier League twice and one Champions League.Real Madrid seems the likely destination for the England defender, but what should Liverpool do next - and who could they bring to Anfield?Alexander-Arnold to leave Liverpool at end of season Alexan