The dreadful conditions of the pitch, which had been ruined by torrential rain as well as an intensive schedule of matches, perhaps contributed to Nastasic suffering the injury to his ankle, just a couple of days after Spurs defender Jan Vertonghen suffered a similar sprain.
BBC Sport report that manager Manuel Pellegrini dismissed the pitch being directly responsible, while he also alluded to not knowing how long the defender would be missing for until scans took place back in England:
It is part of the game and could have happened on any pitch. We are concerned but it is better to wait. He received a kick to his ankle and the doctor is seeing what it could be, but it is impossible for him to know. The doctor needs to see him when we arrive in Manchester and then we can know what has happened.
Of course, with the extent of Nastasic's injury not yet known, it could be that the defender is back before City's season opener against Newcastle United on August 19, but he could also be out for significantly longer, particularly if there is ligament damage to the ankle.
Nastasic was a regular for City last season immediately after signing for them last summer; he played 21 times in the Premier League and featured in five of their six Champions League matches, impressing viewers with his calmness on the ball and defensive prowess.
City have signed four players so far this summer, but all play in the final third of the pitch with the exception of energetic midfielder Fernandinho. For certain, no defensive additions have been made—though two departures, Kolo Toure and Maicon (plus, technically, Wayne Bridge), means they are looking a little light at the back.
With Nastasic sidelined, their natural central defensive options are now narrowed to Vincent Kompany and Joleon Lescott.
As a pairing, those two have plenty of experience of course, with both playing often as City won the league two seasons ago.
Micah Richards and Jack Rodwell can also both fill in there as needed, but the odds are that if Nastasic is out for an extended period of time—or indeed if he gets injured again later in the season—City are going to struggle if they don't invest in another centre-back.
Manuel Pellegrini has only been in the City job a matter of weeks, but Nastasic's injury will likely force him into another decision in the transfer market, and one which will likely take City's spending over the £100 million barrier for the summer.