It is almost a year since Rafael Benitez was invited to consider the deterioration of what had once been a relationship fuelled by healthy respect. "We were good friends until Liverpool started winning," said the Spaniard of Jose Mourinho, whose Chelsea side he was preparing to confront for the 14th time in under three years in the first leg of the Champions League semi-final. Familiarity had bred contempt. History may now repeat itself.
Benitez had clasped hands with Arsène Wenger in friendship prior to kick-off here, the pair sharing a nod and brief muttered word of acknowledgement as the pre-match din whipped itself into its glorious frenzy, before retiring to their dug-outs. There has been little antipathy between these managers since Liverpool recruited the Iberian back in the summer of 2004. Their teams have rarely been in direct competition for the Premier League title beyond the onset of midwinter in the campaigns since, last season's cup collisions serving more to irritate Benitez than to enrage him, even in defeat.
Yet this was a different kind of occasion. The two managers stood a matter of feet apart through their third encounter in six days, all a flurry of arm-flapping and puffed cheeks, though by the final whistle they were worlds apart.
Their teams' respective seasons depended upon progress here. Wenger may have talked up his side's prospects of reviving a flagging title challenge in the build-up but, with Manchester United six points away and his own team having won only once in eight league games, it was hard to accept such optimism as anything but mind games aimed at cajoling form from players whose self-belief has been on the wane.
Yet, by the end, Arsenal had effectively been cast adrift. There was sympathy to be had in the post-match handshake, but no consolation. Given what was at stake, this was always likely to test friendship to the point of fracture.
Wenger, of course, had had his own public disagreements with the Special One - just as he had with Alex Ferguson when there were only two powerhouses competing regularly for the Premier League - but it was the implications of defeat in those critical encounters between Chelsea and both Arsenal and Liverpool that had fuelled the resentment in the dug-outs.
Mourinho's nouveaux riches had tipped the balance of power in the capital with a recruitment policy as far removed as possible from that favoured by Wenger. They never saw eye to eye.
There had already been signs of tension developing between Wenger and Benitez in the build-up to this match.
Ironically, back in the September of 2006, Benitez had put down the deterioration of his relations with Mourinho to the Portuguese's regular public appraisals of Liverpool's style and team.
"I've never spoken about his team," he said at the time. "We should be talking about things on the pitch, not matters off it."
Yet it was the Spaniard who had moved to dismiss the perceived wisdom that Arsenal are a youthful side in the build-up this time.
It fell well short of a Mourinho dig, but it still grated with Wenger. There was an element of truth to his comments, conceded the Frenchman. "But I cannot say they're old, I'm sorry," he added of his side. "We'll be better in two or three more years because we'll be even more experience, and we'll still be very young then."
The validity of either manager's arguments was immaterial. What the pre-match rumblings had merely suggested was that it may only be a matter of time before these two are refusing to shake hands after games.
For the moment, it will be Wenger who feels less inclined to share. Fernando Torres, a player he had courted but for whom he had been unwilling to pay £22 million, scored the goal that effectively catapulted his hopes of gleaning silverware for another season here.
A hopeless pursuit of the Premier League summit awaits, followed presumably by a summer of contemplation as to whether his philosophy on recruitment needs to be rethought.
It is the type of dilemma which might prompt some to turn to friends for advice, though allies may be in short supply.