The Latics chief was disappointed with his midfield in particular during a match where they trailed for 85 minutes after Clayton Donaldson's header gave the Bees a fifth-minute lead.
Oldham - who shocked Nottingham Forest in the FA Cup last week - created half-chances, but Matt Smith, Jose Baxter and Cliff Byrne couldn't seriously test visiting keeper Simon Moore.
Donaldson pounced again eight minutes from time, slotting in from 12 yards, to leave Dickov plotting new additions to his squad.
"That was really disappointing after what happened in the cup last week," he said. "We know Brentford are a good team who are up there, but we were lacklustre with and without the ball.
"It was a nearly game for us and we could have got something out of it with an extra 10 per cent to our performance.
"We have to show the same effort and desire in every game but, with the way we played, I couldn't really see us winning.
"Compared to Brentford we were a bit lightweight in midfield and I'll be looking to bring people into the club if possible."
Oldham, however, have received a major boost with top scorer and playmaker Jose Baxter signing a new two-and-a-half year contract.
Dickov said: "It's a fantastic signing. The fact he has shown such commitment to the club should be applauded. When you look at the way he has been playing, you couldn't have held it against Jose had he decided to move."
- Sports & Recreation
- Jose Baxter
- Clayton Donaldson