Vincent Kompany is likely to miss at least two games for Manchester City after straining a calf in the FA Cup win at Stoke. The City captain is certain to miss the trip to Queens Park Rangers on Tuesdaytomorrow and may still be doubtful for Liverpool's visit to the Etihad at the weekend.

David Platt, City's assistant manager, said: "I think we'll lose Vincent Kompany for a little while. It's too early to say how long he will be out but he has a slight pull on his calf and will miss the midweek game. We will have to assess the injury over the next 24 hours to get a better picture."

Kompany himself did not seem too despondent, tweeting his congratulations to his team-mates on staying strong and recording a fifth consecutive clean sheet, though one way or another he seemed destined to take an enforced break at this stage of the season.

No sooner had City's appeal against Mike Dean's harsh red card against Arsenal overturned a three-match ban than injury intervened to sideline the defender at a time when the club have already lost Kolo Touré to the Africa Cup of Nations and are slightly thin on cover. They survived at the Britannia by switching to a back three and then pressing Gaël Clichy into service as an emergency centre-half, though the chief irony in a disappointing Cup tie was that Stoke themselves should have been down to 10 men after Glenn Whelan perpetrated a flying, studs-up assault on Javi García's ankle that was far worse than the clean Kompany challenge on Jack Wilshere that was deemed so dangerous.

If consistency is ever to be achieved in this vexatious area it can be only through the use of video replays and retrospective charges. Whelan can expect to hear from the FA after Howard Webb took no action, seemingly because he and his officials missed the incident that left García howling in pain. Replays quickly established it was as clear a red card offence as you will see, and Webb appeared to have a good view of it, though he may not have had the ideal angle to be sure that Whelan had left the ground.

The Stoke player jumped two-footed for the ball and ended up making contact only with García, and while Webb may have been sensible in declining to make a decision based on guesswork, it was surprising, to say the least, that he did not even see fit to blow for a foul.

The rest of the game followed a script that is becoming familiar to Manchester City fans, with their side effortlessly superior in most parts of the pitch but unable to translate their pressure into goals. It was the same in the league game against Fulham last week, when City were handed an early goal and responded by switching off for the next hour. At Stoke, as the game entered the last half-hour still goalless, Roberto Mancini removed a defender and threw on Sergio Agüero to boost City's frontline attack to four, yet still the decisive goal arrived only five minutes from time and it was a defender who scored it.

There is no more popular player in the Manchester City camp at the moment then the tireless Pablo Zabaleta, however, and at least David Silva, Agüero and Edin Dzeko were all involved in the move that finally removed the threat of a wholly unwanted replay. Taking advantage of a nondescript touch by Dzeko that had the effect of taking out a defender and rolling the ball helpfully in his direction, Zabaleta arrived in the penalty area to stab the ball past Thomas Sorensen.

"Pablo is always getting up in support of our attacks. It wasn't a surprise to see him come up with the winning goal," Platt said. "He gives us a lot in defence and attack, he's your eight out of 10 man every week." If anything, that sells the full-back a little short because what City are not quite getting from the illustrious names up front at the moment is similar consistency. Kompany is right to stress the importance of clean sheets and a tighter defence, but if City are to have any chance of catching United in the league, or adding another FA Cup to their honours under Mancini, they could do with one or two days when their front men manage to click.

Man of the match Pablo Zabaleta (Manchester City)