A combination of lack of fitness and a long-haul flight from South America contributed to Coutinho - who was heavily linked with a move to Barcelona during the transfer window - missing out on the 5-0 defeat at the Etihad Stadium.
However, Klopp has suggested that Coutinho would not have changed the outcome of the game, as well as indicating that the decision was made with consideration to the club's upcoming fixtures.
The 50-year-old is quoted by The Mirror as saying: "With Phil, we didn't always create more chances against City in the past. Yes, we scored more often in some games. But this was the decision we took [to leave him out].
"If people blame me for this, no problem, but it was a decision taken for the season. He came back after a long flight, after three weeks without playing.
"We have matches next Wednesday, next Saturday - we play, play, play, so we thought 'Let's give him three or four days' proper training – and then he's available for us'."
Coutinho could be involved when Liverpool host Sevilla in the Champions League on Wednesday night.