The Blaugrana were mentioned closely in connection with Coutinho earlier this year and apparently see the Brazilian as the long-term successor to Andres Iniesta in Catalonia.
While that speculation had seemingly died down somewhat over recent weeks, fresh reports from The Mail on Thursday evening (20 July) suggested that the La Liga giants had submitted an €80m (£71.6m, $93.1m) bid for Coutinho that was believed to have been instantly rebuffed.
"Yes, that's what you can say, but that's not since this morning or yesterday, I'm not sure it was different at any time," Klopp was quoted as saying by Sky Sports at a press conference held in Hong Kong when asked if Coutinho was absolutely not for sale.
"Phil is a very, very important player, but we need to react better when he's not on the pitch, that's how it is.
"He was out for a few games [last season] and when he came back he was not in the best shape to get back into his rhythm. With his quality, he has all the pressure to do it on the pitch. We have to do better in moments like this. Phil can of course improve, but there's no doubt about his qualities. He's in good shape, good games, good movement, very smart in both parts of the game, offensively and defensively."
Barcelona have been criticised for making a rather pedestrian start to the summer transfer window that has thus far only yielded the signings of Marlon Santos, Gerard Deulofeu and Nelson Semedo.
The club may also lose one of their formidable 'MSN' attacking trio over the coming weeks as rumours linking Neymar with a sensational €222m world-record switch to Paris Saint-Germain continue to gather pace. 33-year-old Iniesta, meanwhile, is entering the final year of his contract at the Nou Camp and has so far yet to agree an extension.
Coutinho has established himself as an instrumental figure for Liverpool since arriving from Inter Milan for just £8.5m back in 2013, and scored 14 goals during a 2016-17 campaign in which he missed almost seven weeks due to ankle ligament damage.
Not a selling club
Klopp has been adamant that Liverpool have not and will not lose any players that they wish to keep, describing it as perhaps the best news of the summer. He is now eager to reiterate that the Reds are simply not a selling club.
"I'm not surprised that any club is interested in players at Liverpool," he added. "The very important message is that we are not a selling club and that's how it is. We believe in working together and developing together. We want to make the next step together and for this we need to stay together.
"We have to create a situation where everybody is easily able to see which direction we want to go. It's really positive. This is a fantastic club and it's a good moment for Liverpool."