The Merseyside giants suffered a damaging 3-1 defeat at the Gtech Community Stadium to leave their top-four hopes further dented.
Liverpool were on a four-game winning streak ahead of the trip to Brentford, but Owen indicated that those victories were papering over a few cracks.
He stressed that the warning signs were already there given how many chances they were conceding and the number of saves Alisson was being forced to make due to a brittle defence.
The former striker admitted that playing away at Brentford was their worst nightmare given how aggressive Thomas Frank’s side are when they are playing at home.
Owen said on Premier League TV: “The warnings were there, weren’t they?
“We highlighted them before the game – how many shots are being conceded, how many chances, how many chances and how many saves Alisson was making.
“We have seen this coming for the last couple of games, since the World Cup and before that, for that matter.
“It’s not been a good start to the season at all, they have looked vulnerable at the back and to say we could see it coming would be an understatement.
“It was their worst nightmare, going to a place like this, playing against a top side with aggression, it all came crumbling down for Jurgen Klopp’s side.”
Liverpool are four points behind fourth-place Manchester United who have a game in hand over Klopp’s side.
