Barcelona are looking to offload the Brazilian, who they bought from the Reds in January 2018.
After winning the Champions League last season, Murphy thinks Jurgen Klopp's are doing fine without their former talisman.
Former Reds star Murphy told bwin: "Liverpool would be taking a step backwards if they re-signed Coutinho. Coutinho is at his best when playing in a central three, not wide left. If he were to come back, he would change the dynamic of the team and it would disrupt the balance.
"Liverpool's midfield three are all super-athletes who defend as much as they attack, which they'll lose if playing Coutinho there. Klopp had the ability to try a different formation once Coutinho departed and the results speak for themselves. It would be risky to revert back to accommodating Coutinho.