Monchi said Alisson will only leave Roma if he comes out of retirement as the sporting director reiterated the club's stance not to sell the star goalkeeper.
Alisson enjoyed a stellar season for Roma, the Brazil international helping the Italian side to the Champions League semi-finals.
The 25-year-old's exploits have not gone unnoticed with Liverpool, Real Madrid and Paris Saint-Germain among the reported suitors.
However, Monchi – a former goalkeeper at LaLiga outfit Sevilla where he spent nine seasons during the 1990s – insisted Alisson is not for sale.
Speaking as he received his forward for the best sporting director of the season in Serie A, the 49-year-old said: "Alisson? If he leaves, it's just because I've gone back to being a goalkeeper!
"This is the only way he'll leave, but I don't know if I'm ready to play again."
Alisson made 37 league appearances – conceding just 28 goals – as Roma finished third in Serie A.
Roma team-mate Edin Dzeko also starred for the capital club with 16 Serie A goals in 2017-18.
Dzeko, who was close to joining Premier League side Chelsea in January, scored 24 goals in all competitions.
"He'll stay with us," Monchi said. "I expect him to have a similar next season to this one. We all want him to stay."
Mochi also revealed Roma will hold contract talks with head coach Eusebio Di Francesco and full-back Alessandro Florenzi, who has emerged as a target for rivals Inter.