The Algerian limped off to be replaced by Portuguese midfielder Silva, who scored the goal his team's display had deserved on the stroke of half-time.
While the Citizens' youth has been the main focal point since arriving in America, the club has brought along two key figures in the attacking third, with Leroy Sane and first-year winger Riyad Mahrez - who joined from Leicester City this summer.
"A lot of the players went really far in the World Cup".
He said: "I was not concerned about it otherwise he wouldn't have played".
Silva's exploits with Spain have coincided with the most successful period in the country's history, winning the 2010 World Cup between back-to-back successes in the European Championship.
Craig's appearance came after Salah and Mane left City shaken - but not stirred - in a strong performance, with both players getting on the scoresheet.
The best way to show his quality and maturity is by stepping up when City need him most and Sane could just be Guardiola's most important player in the opening weeks of their title defence. I am happy to be manager of these guys for this reason.
"I think it makes it good because the competition improves the players, improves the squad, improves the team". We will see which players we have for the final against Chelsea, how many players and in which condition, we will see, and then comes the start.
Nine minutes later, Niko Kovac's charges doubled their advantage as Franck Ribery's lofted ball over City's back line was controlled by Arjen Robben and calmly slotted over Claudio Bravo. But the Catalan coach hinted that some of the youngsters who have impressed in the United States could remain with the first team. And I don't get arrogant [and think] that I will be more successful than him. "I will not say names because at that age normally you say names and it will confuse [the situation]".
"I was disappointed for them too because some of them are my friends and I've played with them before, " he added.
Mane came on at half-time and nearly opened the scoring within three minutes, when he scrambled a shot past Hart only for Eric Garcia clear his effort off the line. But I'm so satisfied for the intention.
"First we have to try and be successful and after that I have to accomplish quite a lot to even be considered near Pep Guardiola".