The inconvenience of international friendlies, the uncompromising fixture schedule, the ghastly weather or the oppressive top rate of income tax - whatever it was Jose Mourinho and Rafael Benitez seemed to be agreeing upon in their pre-match pitch-side chat on Wednesday night, it was unlikely to involve football. They have been here only one year but for all their modern approaches, these managers could scarcely have embraced the English culture of feuds and grudges more wholeheartedly.
From Mourinho came an attack on the "basketball football" that he perceives to be at the heart of Liverpool's long-ball game and in return from Benitez came the suggestion that Chelsea are "afraid" of his team. They will have to abandon the cosy small-talk and perfect the art of the handshake without eye contact to match the rancour of Sir Alex Ferguson and Arsène Wenger's antipathy but there is a rivalry in the making between this pair that promises to be just as engrossing and long-running.
Ahead of tomorrow's rematch, Benitez has given hints as to how he thought Chelsea approached their first visit to Anfield since last season's European Cup semi-final: the distinction he made was that Mourinho's team were one of the "strongest" but there were no compliments for style.
"I like the way Arsenal played two or three years ago a lot, and I like the way Barcelona and Milan play, that is much better football," Benitez said. "But it is very difficult to say who is the best team in the world. What about Santos, Boca Juniors?
"You don't have to play beautiful football to be the best although you have to play as well as possible and you have to win. Real Madrid have won trophies for a long time and Chelsea have only started. I hope people talk about us like that soon, but with respect."
After the inconclusive nature of their Champions' League game comes a return to the Premiership in which Mourinho dominates. The replica tin-foil European Cups that the Anfield crowd waved in his direction on Wednesday will count for little when Liverpool take stock of the 37 points that stood between them and the Premiership champions last season. A defeat for the home side and it might be over for them before the chill of the English season sets in.
So what did we learn from Wednesday's game? That Chelsea can be pressed back, that they can be stifled and they can be dominated but if Liverpool want to score against them as well then they have to learn some new tricks. It also became clear why Benitez, more than Wenger and Ferguson, is likely to prove an irritant to the empire Mourinho is trying to build.
Tactically, and in the terms of their football culture, both men occupy the same territory: they are both conservative in their approach to winning football matches. Against Ferguson and Wenger, Mourinho can take that position without fear of comparison. Against Liverpool, he and Benitez can, at times, resemble two generals refusing orders to advance.
The difference comes in the gloss they place upon their methods. From Benitez comes talk of careful development, gradual progress and the rebuilding of a club that, despite their unlikely triumph in Istanbul, know they have a long way to travel to become champions of their own country. From Mourinho comes the rather less bashful assertion that Liverpool were not worthy winners of the European Cup.
Tomorrow would be a good chance for Mourinho to start offering up evidence to back the wide-ranging claims he made when he first arrived in Liverpool this week, but especially those about Anfield's legitimacy to be champions of Europe. Because for a team whose achievements he holds in so much contempt, Mourinho's reluctance to commit so little to attack at Anfield on Wednesday suggested that he has a higher opinion of the opposition than he conceded.
If Chelsea are capable of ending the title race before Christmas, if they are the club of the next decade with the resources of Roman Abramovich's fortune, then tomorrow represents a chance for them to do more than play for a draw at the home of the club that finished 37 points behind them last season. The excuses for Wednesday's game - that it was a night for Champions' League caution rather than Premiership abandon - no longer apply.
Mourinho will resent the pressure to attack without remorse but his proclamations of supremacy will start to sound a little empty if he settles for a point against an opponent he has spent so much time belittling.
Steven Gerrard's assertion yesterday that Liverpool might be "a little more adventurous in certain areas" suggests that they are ready to attack. Chelsea might start by asking themselves why they are so afraid to do the same.
GERRY FRANCIS TALKING TACTICS, PAGE 57