Liverpool would benefit from developing a mischievous streak
Liverpool know only too well the value that Diego Costa brings to a team.
That's why they submitted a £21.85m bid to Atletico Madrid to trigger a release clause in his contract and make him the third most expensive player in their history in August 2013.
When the deal did not happen there was a belief - never substantiated - that Jose Mourinho had encouraged Jorge Mendes, the agent he and Costa share, to help cool it because he had designs on taking the striker to Chelsea.
Costa and Luis Suarez in the same Liverpool team.
What a prospect would that have been? Too much of a bad thing, some might say.
But the reason why Liverpool pursued him those two summers ago was the same reason why Brendan Rodgers' criticism of Costa was so temperate late on Tuesday night.
The manager knows that Liverpool need some of what Costa gives a team.
The South American term for it is picardia - the sort of spice you use to steal an advantage. The Brazilians call it jeitinho - accomplishing goals by flying in the face of social convention. Stretching the boundaries of cheating, by any other name.
No one is pretending that what we saw Costa do in the course of Chelsea's 1-0 Capital One Cup win at Stamford Bridge - stamp on two players - was anything approaching justifiable.
But to have witnessed what else he delivered in Tuesday's game - agitating, distracting and bothering opponents - made you recall the aspect of Suarez's game which is almost irreplaceable, now he has left Anfield.
There was plenty of good in what Liverpool delivered in the semi-final.
They demonstrated in the two games against Chelsea something they were incapable of at their highest point last season - defensive steel and an ability to close the door on opponents.
Lucas Leiva is one of the most important players in the Liverpool team now. Rodgers has always been willing to turn back to players he seemed to have given up on.
The relocation of Raheem Sterling to the top of the strike force is allowing Liverpool to stretch the game as they did last season and bring out the best in Philippe Coutinho by creating space for him. Rarely can a team have taken as much encouragement out of a semi-final defeat.
Yet, for all that, Rodgers has been done by Mourinho once again - no victories in their seven encounters now - and important components are missing.
A capacity to score is the most elementary. Daniel Sturridge's return will help but he is not a panacea for their attacking ills. Others must begin to deliver goals.
Jordan Henderson has only 13 in 123 appearances - not enough - and, though Coutinho's strike rate of 10 in 65 is better, he has only two this season.
Mario Balotelli is a write-off, incapable of causing the type of preoccupying threat that Costa can. It is very surprising that Rodgers is intent on keeping him until June.
But having seen Chelsea do what they do, it is also hard to avoid the sense that this team also need one of the London side's less desirable components - a little more devilry.
The development of Henderson has been gratifying but is he actually cut out to be Steven Gerrard's successor - snapping into tackles in a way which puts fear into the opposition?
The sense that Liverpool are a little too nice has been pervasive ever since Rodgers took over in 2012 and it is more discernible than ever now that Suarez has gone.
So, Liverpool will curse Costa, as Emre Can and Martin Skrtel rub their bruises.
But they will also tell you that some of what that player brings is good for the soul - and Mourinho certainly knows that.