Coutinho, 25, only signed a new deal reportedly worth around £150,000-a-week in January, making him the highest-paid player at the club.
However, the Brazilian's future at the Merseysiders has been thrown into question after it emerged that Barcelona have identified him as priority target for the current transfer window.
Klopp has reiterated in recent days that Liverpool want to keep the Brazil international but reports in Spain say that Barcelona are still confident of convincing the Premier League giants to cash in on in a deal worth around €100m (£89.5m, $118.3m).
Coutinho is also said to be keen to make the move to Nou Camp, with reports assuring that he has even already agreed personal terms with the Catalans ahead of completing the move.
Moreno, however, still hopes the Brazilian will continue at Liverpool after having built a strong relationship with his teammate since arriving to the club from Sevilla in the summer of 2014.
"I'm very close to Coutinho. We are very close friends. We are all day together. There have been many rumours [about his potential move to Barcelona] but he is calm, he is working hard. I think that the clubs have to make a decision and let's see what happens. He's calm, he's still working hard and he's happy in Liverpool. I hope he stays here," Moreno said to Cadena Ser.
Pressed on whether Coutinho has already made a decision on his future, Moreno said: "You have to ask that question to him. I do not know."
On Tuesday [1 August], Klopp told Barcelona to forget about signing Coutinho after he enjoyed another impressive performance during Liverpool's 3-0 win over Bayern Munich in the Audi Cup.
"I can understand that Coutinho is so highly rated, but they can save their energy," the manager said in a press conference.
However, Barcelona are still expecting to test the resolve of Liverpool with a big money offer as the Catalans are already preparing for life without Neymar.