The Brazilian returned to first-team training from an apparent back injury on Thursday, having featured for Brazil over the international break - scoring from the bench against Ecuador and also making an appearance as a substitute versus Colombia.
His return comes after months of trying to engineer a move to La Liga giants Barcelona, who had several huge bids rejected for the attacking midfielder since July.
But the Reds' unwavering resolve saw them keep hold of the prized 25-year-old, though Klopp feels that it makes no sense for him to make an immediate return to the match-day squad at the Etihad Stadium.
Coutinho - who is yet to play for Liverpool this season and had a transfer request rejected earlier this month - returned to Merseyside on Thursday after the Reds teamed up with this weekend's opponents City to ensure their Brazilian contingent's early return via private jet.
Klopp says midfielder in a "very good mood"
Previewing his side's trip to Eastlands, Klopp told reporters at his pre-match press conference: "He went to the national team and trained normally, but now we have to prepare for a normal season so we have seven games [before the next international break] and we saw training this morning and thought 'Okay, maybe we should use him immediately' because he was really good, but that doesn’t make sense."
Instead, the German says Liverpool "have now to continue with the pre-season" for Coutinho but "not too long" and added: "In a few sessions we have to give ourselves the time, because in the next month we have seven games."
He continued: "We always have the same decision to make, 'Does he need training or can he play?' and all that stuff."
Klopp noted that the Reds' No.10 must now "do a little bit more than the other boys" but said that he "showed up in a very, very good mood" and "looks really promising."
On Coutinho's compatriot Roberto Firmino, Klopp said that he "played in the second game a little bit longer" but assured that "both fit" and "healthy."
Coutinho's actions not "unforgivable"
Klopp revealed that he and Coutinho "had a very good talk" but did not discuss the details, insisting that his training was "even better" than the "very good mood" he was in.
"But I had to make the decision [to leave him out of the City squad]," continued Klopp. "We have seven games in the next three weeks. There will never be time to train so we had this conversation."
The German said that Coutinho has to be prepared "for the rest of the season" which is "quite difficult" with their "fixtures" and "schedule" in the near future.
Klopp feels that Coutinho will benefit more from "four or five days" of "real and proper training" rather than playing "15 or 20 minutes" in the City game.
"He agreed completely. It was not that he said 'No, I don't need training, I want to play' or whatever. It was a good conversation," said the Reds boss.
The legitimacy of Coutinho's injury - which kept him out for Liverpool's first five games of the campaign including a key two-legged Champions League qualifier against Hoffenheim - has been questioned after he was considered fine to feature for Brazil.
But leaping to the player's defence, Klopp dismissed speculation of the playmaker feigning the injury, saying: "I know what people think, but Phil had a back problem a few weeks ago and couldn't train, so that means he misses around about three weeks."
The manager also noted that his working relationship with Coutinho has not been affected despite his attempts to leave for Barcelona.
Klopp praised Liverpool for handling the saga "really well" as he insisted that "not all the things in newspapers were 100 per-cent right" between the club and the player.
"But it is normal a lot of things were coming up in a situation like this," he acknowledged. "Nothing I am aware of was unforgivable. The most important thing is no one told me anything where I thought 'Oh, that is too much'. He came in, accepted 100 per-cent the situation. I didn't even have to say anything about it."