The Reds saw the Brazil international depart Anfield at the end of a long-running transfer saga in January 2018.
The South American playmaker had made no secret of his desire to try his luck at Camp Nou and was granted his wish once a big-money offer was tabled.
Coutinho’s dream has become something of a nightmare in Catalunya, with the 27-year-old struggling for the form required to justify the sizeable fee invested in him.
Liverpool, in contrast, are now Champions League winners and Premier League title challengers, with Jurgen Klopp having found a way of countering the loss of a creative influence.
With that in mind, former Reds striker Mellor has told American Gambler when quizzed on whether a move should be made to bring a familiar face back to Merseyside: “I think Coutinho was a great player for Liverpool and I really did enjoy watching him.
“He had creative influence to make things happen and of course, I was disappointed when he left.
“Leaving for Barcelona for whatever reason, he hasn’t shown the same quality at Barcelona that he did at Liverpool.
“One of the biggest compliments that you would give the current Liverpool side and Klopp, is that they didn’t really miss Coutinho.
“They went from competing for the top four to competing for a title without Coutinho and won the Champions League.
“He was a great player for Liverpool and loved watching him, but he hasn’t been missed.”
Plenty of comings and goings are currently being mooted at Anfield, with Coutinho being talked up by some as a possible arrival.
On the departure front, Croatia international defender Dejan Lovren is said to have become a target for Serie A giants AC Milan.
Reports suggest exit talks have been opened, but Mellor believes the 29-year-old centre-half should be retained to add depth in Klopp’s squad.
He added: “I think he is a player that benefited with [Virgil] van Dijk’s arrival.
“Whoever has partnered Van Dijk, Lovren being one of them, they have all looked great playing alongside him.
“I know that he has found himself out of the team because of how well [Joel] Matip has played in the second half of the season.
“As a third or fourth choice centre-back, I don’t think Liverpool should be in a hurry to get rid of him because of the cover that he provides in that position.”