Souness wrote for the Daily Mail: "Against the weaker teams, when Liverpool are dominating the ball, that new midfield role will be perfect for Trent. But against the better teams, I feel there may be a problem for him and his team.
"In that central part of the pitch, everything is happening faster than anywhere else and your thought processes need to be that much quicker.
"If you're not calculating what will happen at full back, where there is more time, then you will certainly find it difficult to do so in the centre — against the stronger sides, at least.
"But as a manager, you would always want such a rare talent as Trent's in the final third for you — shooting, picking a pass, delivering the ball with an ability surpassing anyone else in the Premier League.
"Liverpool saw that from the very start, because Trent was a midfielder before he became a full back. It was from midfield that he scored two goals for Liverpool's Under 18s, while still a 16-year-old, against Manchester United at Carrington back in 2015.
"There must have been a reason why he was moved to the role at full back."