You can imagine what Pep Guardiola was thinking when he found out that John Stones had been forced off injured during England's recent 3-3 draw with Germany.
The Manchester City defender went down clutching his right hamstring in the 36th minute of Monday night's thriller at Wembley, and was replaced by City teammate Kyle Walker. Gareth Southgate confirmed after the match that Stones' issue was indeed hamstring related, but as of yet no timescale has been put on his absence.
Given the nature of hamstring injuries, it would be remarkable if Stones is fit enough to feature in the Manchester derby on Sunday. In the two weeks that follow City will face FC Copenhagen both home and away in the Champions League, a home match against Southampton and then a clash with Liverpool at Anfield, their toughest test of the season so far.
Depending on the severity of his injury, Stones could be unavailable for all five of City's upcoming tricky encounters, joining Aymeric Laporte as another centre-back on the sidelines.
Perhaps predicting that centre-back injuries might become an issue this season, City made an uncharacteristically late dip into the transfer market to sign Manuel Akanji from Borussia Dortmund. The move for the centre-back was surprising, as was his fee of only £15m.
Guardiola predicted Stones' injury before the 4-0 win at Sevilla last month, justifying his transfer.
"We are lucky the club give me Manuel Akanji otherwise we be in real trouble. The club moved quick to bring in another player in this positions. The history for John and Nathan [Ake] they aren’t quite reliable to play every week. It is what it is. Mainly because this incredible schedule for many years, the players cannot sustain it for a long time."
Akanji has started all three of the City games he has been available for and has impressed, particularly in the 3-0 win at Wolves. Not only does he look defensively solid and a leader, but he appears capable of replicating the kind of progressive passing that Stones and Laporte excel at, but that Ruben Dias and Ake aren't quite as good at. Guardiola highlighted the quality himself.
Already Akanji looks a bargain, but with respect to Sevilla, Borussia Dortmund and Wolves, greater tests await the Switzerland international. The first of those will come on Sunday against a resurgent Manchester United, the likes of Antony, Marcus Rashford and Jadon Sancho bound to keep Akanji on his toes.
Should Akanji keep his place in the starting XI with Stones and Laporte out injured then he could well start at Anfield on 16th October, a stadium where the likes of Mohamed Salah and Roberto Firmino have really hurt City in recent years.
Should he pass the tests that face him over the next month or so and City head into the World Cup break in and around the top of the Premier League table, then Akanji might find himself considered one of City's best value signings ever.