Andrew Robertson (£7.0m) broke the record points total for a defender in Fantasy Premier League last season with a score of 213.
"Me and Trent always keep a close eye on it. I think he fancies to beat my record that I set last season," Robertson revealed on the latest FPL Show.
Alexander-Arnold, who produced the highest ever individual Gameweek score for a defender in FPL with his 24-point haul against Leicester City on Boxing Day, currently has 112 points this season.
And Robertson, who trails the right-back by 14 points, conceded that if forced to choose between himself and Alexander-Arnold, he would select his team-mate.
"I'd say sign Trent," he said. "He is pricey, but he does produce to be fair to him."