The 25-year-old, who played in all of Brazil's run to the quarter-finals of the FIFA World Cup, is already in Liverpool ahead of his medical tests before joining the five-time European champions.
According to media reports, Liverpool will pay Roma 75 million euros ($87.1 million) to buy Alisson, who had joined the Italian capital outfit for eight million euros ($9.2 million) in 2016 from Internacional.
Monchi said the offer was too tempting even if it meant selling one of their best players.
"First of all I want to say that nothing is finalised yet. Alisson is in Liverpool and we're at a very advanced stage, but the deal is not done yet. If everything goes smoothly, it will be finalized soon," Monchi was quoted as saying by Roma's official website.
"Economic factors are important for the club too, not just sporting factors. The offer was way above the market average -- it was very significant. We weighed up the pros and cons and decided to speak to Liverpool in order to come to an agreement."
If the signing is completed, then Liverpool will smash the record of most expensive goal-keeper signing in world club football record history. The current best is 53 million euros ($61.5 million) Juventus paid Parma in 2001 to sign Gianlugi Buffon.
Alisson played a big role last season as Roma reached the 2017-18 Champions League semi-finals, losijng to Liverpool. Roma also finished third in the Serie A.
Monchi denied that Roma lack ambition as they continue to sell important players. In 2017, Roma sold Egyptian forward Mohamad Salah, German defender Toni Rudiger and midfielder Leandro Paredes.
"The job of a sporting director is not just to make signings but also to understand what's best for the club at any given time. Does it show a lack of ambition? Not for me. It's nice to talk about ambitions, but you need to use your head," he said.
"Our ambition remains unchanged. We've sold two important players, Radja (Nainggolan) and Alisson, but we've signed ten players very early in the window. We continue to work hard to find players and build a great team."
Spaniard Monchi, however, was happy with the signing of young forward Justin Kluivert from AFC Ajax.
"It wasn't an easy deal. Given the calibre of player he is and the amount of potential he has, lots of clubs were after him. It gets a lot easier when you get to the point where the player wants to come here.
"The first meeting we had was really important because it was a chance to show him that AS Roma was the perfect place for him at this stage in his career."
(This story has not been edited by Social News XYZ staff and is auto-generated from a syndicated feed.)
