Fernando Hierro has been installed as the axed manager's successor ahead of the tournament, but several reports in Spain have claimed that the players attempted to convince the Spanish Football Federation (RFEF) to allow Lopetegui to stay on.
Ramos has now taken to Twitter to issue a rallying cry to supporters, insisting that La Roja remain focused on clinching glory in Russia.
"We are the National Team, we represent a shield, colours, fans and a nation. The responsibility and the commitment are with you and for you. Yesterday, today and tomorrow, together. #VamosEspaña."
Lopetegui did not lose a game during his tenure, guiding Spain to 14 wins and six draws in his 20 matches in charge.
Indeed, Spain qualified for the tournament in Russia unbeaten, winning nine and drawing one of their qualifying matches, eventually finishing five points clear of second-placed Italy.
Somos la Selección, representamos un escudo, unos colores, una aficion, un país. La responsabilidad y el compromiso son con vosotros y por vosotros. Ayer, hoy y mañana, juntos: #VamosEspaña pic.twitter.com/rzy5D5lF8F — Sergio Ramos (@SergioRamos) June 13, 2018
Ramos has won a total of 155 caps for Spain, and has won two European Championships and the World Cup during his time with the national team.