Seven minutes into last night's match Andy Carroll flew into an attempted tackle on Gaël Clichy, seemingly with both feet. Manchester City's French full-back was deft enough to turn away with the ball and avoid contact. Eighty-five minutes later Glen Johnson made a similar challenge but managed to take the ball cleanly off Joleon Lescott, rather as Vincent Kompany had done in earning a red card for dispossessing Nani on Sunday. Although the home crowd bayed for a response from the officials on both occasions, no cards of any colour were shown.

Kompany watched last night's match from the grandstand, serving the first part of his four-match suspension, but he had made an impact earlier in the day with a thoughtful statement on the subject of his dismissal against Manchester United. Naturally he expressed his disagreement with Chris Foy's decision, and with the FA's rejection of City's appeal, but he did so in such measured and sensible terms that even those who dispute his conclusions could respect his opinion.

The timing of his statement, made via Facebook, was impressive in its restraint. "I waited for the suspension to be confirmed before making any comments on the matter," he wrote, "as I didn't want to give the impression that I was using the media as a tool to benefit my own personal agenda in this case. I'm not speaking on behalf of the club or anybody else, this isn't me defending myself, this is just me raising a genuine concern."

His worry was that referees are making judgments according to a new set of criteria, and he wondered "if we are now going to see an unprecedented wave of red cards on match days, because we sanction 'ifs' and 'maybes'? Are we going to look back at video evidence for every single challenge that goes unnoticed by the officials, look at different scenarios and potential outcomes of what could have been considered a good tackle and then sanction it? Players and managers are starting to expect more sending offs from referees and I think it's for the wrong reasons."

If the game is serious about eliminating reckless challenges, then players are going to be justified in demanding a greater degree of consistency from officials. That is what happened, eventually, when the tackle from behind was outlawed, and the two-footed flying tackle from any angle would appear to be the next target. One can only hope that Kompany is wrong when he suggests that to eliminate what are traditionally thought of as full-blooded tackles would rob the English game of the combination, in his words, of "hardness" and "fairness" on which it prides itself.

The speed and power of the players and the sheer velocity of the game demand modifications, as Kompany seemed to acknowledge. "If football fans decide I'm wrong in raising these concerns," he concluded, "then I will have no problem in accepting the fact that times are changing again for our game." His thoughts showed a mature appreciation of the nature of a debate in which football fans seem evenly split.

The City captain's judgment was badly missed on the pitch in the early stages last night as Liverpool bore forward and the home defence found itself unable to clear its lines, with Joe Hart being forced to make a couple of outstanding saves. Stefan Savic, Kompany's replacement at centre back, had looked uneasy from the start and the Montenegro international, who turned 21 on Sunday, gave the visitors a present when he raised his foot and caught Agger on the knee, conceding what turned out to be the penalty that enabled Liverpool to take an advantage into the second leg.

In a hard-pressed City backline, Micah Richards made his presence felt. Given the captaincy, the burly 23-year-old showed a readiness to lead by example in defence and attack, covering for Savic and driving up the touchline whenever the opportunity presented itself. In the closing moments of the first half he powered past Glen Johnson, cutting in towards the area before producing a fine cut-back, only for James Milner to sidefoot a clear chance over the bar from 15 yards. Richards came close to securing the equaliser himself a quarter of an hour into the second half, charging in to meet Samir Nasri's corner with a clean downward header, only for the ball to rebound off Pepe Reina's knee. Goodness knows how much English football Fabio Capello has watched since he was lasted sighted before Christmas, but it is hard to know what more Richards has to do to earn preferment than hold down a regular starting place in the side that is currently leading the Premier League.

How much damage Kompany's absence, combined with that of Kolo Touré, away at the Africa Cup of Nations‚ will do to City's title ambitions, and their chance of overcoming last night's setback to reach the Carling Cup final, is hard to predict. On the evidence of their last two matches, they miss the influence of Yaya Touré's midfield surges even more.