A brace from Ivan Toney – the last of which came deep into stoppage time – was enough to cancel out Phil Foden’s equaliser and end our 100% record at the Etihad this season.
Pep Guardiola’s men went into the clash searching for what would’ve been a Club record 17th successive home victory in all competitions.
But Gundogan insisted he and his team-mates simply weren’t at our usual standards against the Bees.
“We conceded a goal in the first 20 minutes which we knew was exactly what they wanted,” he explained.
“Sometimes it is difficult to have an explanation. I don’t know, there is no excuse.
“What we did after was ok and we did quite well, but also conceding the second goal like we did is just frustrating.
“It is always tough to analyse, especially when you feel like you were not there, and you are sloppy with the balls and easy passes.
“We also lost possession quite easily and then this transmits to the goal we conceded and the way we conceded it.
“It was way too easy from our point of view to concede two goals today. Unfortunately, that punished us.”
Despite defeat, Gundogan and co. registered 29 shots on the Brentford goal as well as a 75% share of possession.
One of those chances fell the German’s way, but he couldn’t find the target just after the hour following neat build-up play with Erling Haaland.
Rodrigo and Joao Cancelo also forced smart saves from visiting stopper David Raya as we searched for the three points before Toney’s late sucker punch.
Nonetheless, Gundogan highlighted Brentford’s defensive organisation as a key reason as to why we weren’t able to translate those openings into goals.
He said: “It felt like we crossed a lot of balls in areas where Erling was, but he was always against three men.
“I felt like especially getting the ball in between the lines of their defence because their back four or five was quite deep, I felt like there was no space between the midfield and the back five.
“I also tried to make a few runs to the first post and every time I ran there, I felt like I was free because Erling got all of the attention.
“We couldn’t do it well enough today and it is so unnecessary and so disappointing.”