Pablo Zabaleta conceded Manchester City's celebrations over reaching the Champions League quarter-finals were subdued after centre-backs Vincent Kompany and Nicolas Otamendi suffered first-half injuries in the goalless draw against Dynamo Kiev.
City were grateful for the 3-1 lead they carried over from the first leg of the last-16 clash in Kiev after influential captain Kompany suffered a recurrence of his troublesome calf injury in the seventh minute.
Otamendi sustained a dead leg in a challenge with Oleg Gusev to depart after 24 minutes of a listless first half, with Kiev unable to sufficiently test City's hastily thrown together defensive duo of Eliaquim Mangala and Martin Demichelis.
Afterwards, City boss Manuel Pellegrini said Kompany would miss a "minimum of a month", while Otamendi remains hopeful he can feature in Sunday's crunch Manchester derby.
"We were happy because we went through to the next round but obviously [less so] when you see team-mates [injured] - especially Vincent, that is the fourth time he has got an injury this season with the same problem - and also today Nico," Zabaleta said.
"When you lose two big players like this, you want to celebrate but sometimes you just think about them and you feel a little bit down because they are two important players for this team.
"We will see how the medical staff assess the players and see how bad those injuries are. Hopefully not too bad and they can have a speedy recovery."
The excitement levels increased marginally after a dour first half at the Etihad Stadium, with Jesus Navas striking the post for City before a late Dynamo rally was as fruitless as it was futile.
"Of course we are very proud, we made history. We will see the draw on Friday," said Zabaleta, who urged his colleagues not to fear any potential clash with the heavyweights of European football.
"We need to believe in this team that we have players good enough to compete in this competition.
"We need to repeat again another good performance and see if we can go through in the next round."
But first up for the long-serving right-back is the familiar passion and intensity of a derby against Manchester United, with City aiming to safeguard their place in the top four and a four-point advantage over Louis van Gaal's side as the season enters its final stretch.
"Of course, I've been here for a long time. I know this is a special game," Zabaleta added.
"From Wednesday, a few people will be talking about City making history in the Champions League but the main thing will be people talking about the derby - that is normal in this city when a big game is coming at the weekend.
"Let's celebrate the Champions League tonight but I am sure tomorrow the players will 100 per cent focus on the United game."