The 21-year-old also spent some time at Norwich, scoring twice in nine games.
Ahead of his side's game against Arsenal on Wednesday in the Carabao Cup, Canos revealed that he was unhappy with his playing time in Liverpool.
"To sign for five more years at Liverpool, it meant that my career was going to depend on Liverpool, them making decisions for me," he told 'The Guardian'.
"They didn’t offer me the opportunity to try and train and play for the first team. I made my debut but it wasn’t a good thing, I don’t think.
"It was a good thing because then they could sell me for £2.5m to Norwich.”
The Spaniard was also optimistic over Brentford's chances of promotion.
"The future is getting to the Premier League with Brentford. It's definitely possible, you just have to come to Griffin Park and watch us play.”