It's not unusual to see footballers having a very good season followed by a poor one - but to experience a fall in quality as severe as Trent Alexander Arnolds is unusual.
Last season he played 38 matches, scored 4 goals and had 13 assists. The season before that 1 goal and 12 assists in 29 matches.
This season in 16 matches he has had 2 assists and 0 goals playing for the team who has scored the most goals.
AWB who is often considered really poor going forward in comparison has 1 goal and 1 assist in 16 matches.
In addition - TAA has been at best poor defensively, and been at fault for 2-3 goals. His form over the last 3-4 weeks has gone from average to poor, and the player who was considered one of the best in the world in his position just 6 months ago, is now actually lucky he still has a place in the Liverpool-side.
If anyone is trying to convince me that Jurgen Klopp isn't a bit concerned - I don't believe them for a second