I don't think it was easier to find and sign a replacement last summer though. It's clear the club wasn't prepared for Barca to come in for Coutinho - although there was a lot of speculation, I think deep down most people thought that PSG weren't going to sign Neymar and thought it would have ended with a new contract instead. Throw into the mix that we were struggling to land our main targets and there was just no way we could sell him without Barca offering mental money. While still not ideal, the club would have been preparing themselves for Coutinho's inevitable departure for the past 5 months, we've got VVD and Keita in the bag already and will no doubt have somebody lined up should Coutinho go.It's still not clear why Liverpool might be prepared to entertain a Coutinho transfer now, but not last summer when a replacement would have been much easier to find and integrate.
Given Klopp's whole outlook on management, I'm certain he'd rather have a player 100% committed than somebody that wants to leave and while I'm sure the club would much rather a deal happens in the summer, if Barca offer us huge money and we can get a replacement in then they'll accept.