The £125m signing from Bayer Leverkusen has battled to find any form at Liverpool since his summer arrival.
In an interview with Wetbasis, Murphy said: "Talking about the Wirtz subject, one week he's playing with Ekitike and one week he's playing with Isak. The wide player doesn't change on the right but it does a bit on the left.
"He's also had a mixture of midfield partnerships behind him and when you're a No. 10, you start building up relationships with the midfielders. Who's going to give me the ball early, who can I trust and rely on to get me the ball early. If we talk about Wirtz for example.
"So he's got to adapt to this amazing physicality of going to play in Newcastle, or playing against Arsenal, these two physically powerful teams and adapt really quickly.
"In addition to that, adapt to the expectations and pressure of the supporters and the media of what he is supposed to deliver.
"I've seen enough of the brilliant moments from Wirtz to not be concerned. The talent, the vision, the skill set he has is there for us all to see.
"I think his biggest issue is his adaptation to the speed of the Premier League and I know from personal experience, that only comes from playing. Getting your mind and your body used to that."