Ramos remains a free agent after leaving Sevilla at the end of last season.
Monterrey are now in advanced talks with Ramos and his brother and agent Rene about a move to Liga MX.
Demichelis stated: "I always say I don't like to talk about hypothetical situations... I would love, whether it happens or not, if a player with Sergio's career, personality and CV comes here. The club is working very hard to sign another player.
"We need to reinforce the back line with a great player who can help us with the details. Because sometimes rivals score goals against us because of minimal details, which we analyse carefully to understand what we do wrong and what is done wrong in the final stages. Hopefully it will be so.
"It would be an honoyr for Liga MX, for Monterrey (if Ramos comes) - hopefully it can be realised."