A standout 2018-19 campaign has just come to a close for the highly-rated youngster.
Alexander-Arnold contributed 16 assists across those two competitions, before going on to impress for his country in a Nations League third-place play-off clash with Switzerland.
He is considered to have a bright future, with his crossing ability sparking comparisons with David Beckham, and Murphy believes a role further up the field could bring even more out of him.
The ex-Liverpool and England midfielder told talkSPORT of Alexander-Arnold: “Trent is becoming a real threat.
“His crossing is so consistently good, it’s such a weapon. He is consistently putting the ball in ridiculously dangerous areas.
“At the moment with our [England’s] lack of creativity in the middle of the park, I think we have to get this lad in the team constantly.
“I’m not saying we should be relying on a 20-year-old, but when he’s fit, when he’s flying and he’s confident, he has to play.
“We did so well in the World Cup as Gareth Southgate stuck at the three at the back, but now he’s changed to a four and he’s probably got his reasons.
“But if you play a four with England, what you’re doing is restricting Trent a little bit.
“So then how do you get the best out of him? I think it’s a bit further up and giving him that freedom.”
Alexander-Arnold is accustomed to having to provide width at Liverpool, with Mohamed Salah operating in front of him in a forward role that gives him freedom to drift inside.
He is being asked to take on similar duties with England and Southgate has plenty of alternative options at his disposal when it comes to wingers.
Raheem Sterling, Jadon Sancho and Callum Hudson-Odoi are exciting options in those berths, while Marcus Rashford has often been used on the flanks when operating in the colours of his country.