So we learn that the present refereeing fad for punishing potentially dangerous tackles is not compatible with the crazed freneticism of a cup semi-final. The surprise was that only one player was sent off last night given the number of bad challenges.

Caught up in the febrile atmosphere of a relentlessly pacy contest, players operated on instinct and tackled without thinking. Dry directives giving warning that the possibility of causing harm to an opponent is now uppermost in referees’ thoughts, regardless of intent, were far from their minds, even though it can hardly be news given the number of players dismissed in the past month for tackles that would not have warranted even a booking a generation ago.

Avram Grant, the Chelsea first-team coach, recently balked at the idea that he would like to fashion a side emulating Arsenal. But his team increasingly resemble their London rivals during the era when Patrick Vieira stalked the midfield in search of prey. John Obi Mikel’s red card last night was the sixth shown to a Chelsea player this season.

Grant has inherited José Mourinho’s antagonism towards officialdom, yet surely he must accept that the club’s poor disciplinary record is not a conspiracy. Without the injured John Terry, at least Chelsea’s players did not harangue Peter Walton, the referee, with as much vehemence as at Old Trafford earlier in the season, when Mikel was also sent off.

Mikel has now been sent off four times in his season-and-a-half in West London. The Nigeria midfield player was having a superb game, his dynamic athleticism recalling Michael Essien, who has headed to the African Cup of Nations before him. In his final game before leaving for Ghana, Mikel doubtless wanted to make a big impact -John Ob he did, on Phil Neville’s leg.