For the first time in nearly two years, Mourinho's men conceded more than twice with all three Brighton goals arriving before half-time.
Aguero, who turned 30 in the close-season, has now scored 14 times in his last eight Premier League games at City's Etihad Stadium.
After his World Cup exertions, Hazard has been left on the bench for both of Chelsea's opening Premier League victories under Maurizio Sarri.
Arsenal midfielder Mesut Ozil, 29, announced his shock retirement from international duty last month in the wake of Germany's World Cup debacle.
Chelsea's second successive win under new boss Maurizio Sarri lifted them to the top of the Premier League with a 100 percent record.
Mauricio Pochettino's men will host another two home fixtures against Cardiff and Liverpool at Wembley.
La Liga boss Javier Tebas criticised clubs such as Inter, PSG and Manchester City and claimed he had doubts whether the Italian club had the cash to buy Luka Modric.
Usain Bolt has already tried out with teams in Germany, Norway and South Africa, to no avail, since retiring from athletics last year.
Pogba will remain captain for the Brighton game, although Mourinho explained that Antonio Valencia will reclaim the armband when he returns to action following a calf injury.
Argentina will play Guatemala and Colombia next month in the United States, with two more friendlies scheduled before the end of the year.
Kevin De Bruyne will not have to undergo surgery on the injury which he suffered in training on Wednesday.
Claudio Marchisio joined his hometown club at the age of seven and won seven Serie A titles.
Juventus open their campaign on Saturday against a sombre backdrop of a country in mourning following the Genoa bridge disaster.
Mauricio Pochettino believes winning is the only way to keep Spurs fans happy while waiting to move into the club's new stadium.
Ozil, 29, created a furore last month when he retired from international football in an explosive three-part statement in which he accused German FA (DFB) president Reinhard Grindel of racism.
FIFA said its new formula relied on adding or subtracting points, depending on the results of matches, rather than averaging points over a given period of time.
Atletico Madrid scored two goals in extra-time to beat Real Madrid 4-2 in the UEFA Super Cup.