Ramos briefly worked with Modric during his 12 months on the Tottenham bench a decade ago, with the Croatia midfielder moving to Madrid three years after the Spanish coach's short spell with Los Blancos.
Reigning Ballon d'Or winner Modric has won 15 trophies, including four of the past five Champions Leagues, during his seven seasons in Madrid, and Ramos told ESPN FC that Eriksen has shown he also has the level to make an impact at Madrid.
"Without [a] doubt Eriksen is ready to follow in Modric's footsteps and be a success at Madrid," Ramos said at the Santander Media House ahead of Saturday's Champions League final in the Spanish capital. "He is a magnificent player who has been performing at a very high level. He is ready to play at any team in Europe."
Current Madrid galactico Gareth Bale was a young player coming through at Tottenham during Ramos' time at the London club. He said the Wales winger had achieved a lot at the Bernabeu, but was now an easy target for fans and pundits unhappy with their disastrous 2018-19 campaign, and was likely to leave this summer.
"This season has not been good for Bale, but not his other seasons," he said. "Bale has scored big goals, in finals, has performed very well and won four Champions Leagues. But Madrid's last season was very weak. Now it seems the only guilty party has been Gareth Bale. I don't agree with that, but it is easier to blame the one who is leaving, of course."
Ramos remains the last coach to win a trophy at Tottenham -- the 2008 League Cup -- but key forward Robbie Keane and Dimitar Berbatov were immediately sold and not replaced, and club chairman Daniel Levy sacked him early the following season.
The Andalusian said that things had changed a lot at the London club during the past decade, with current coach Mauricio Pochettino having being able to retain his best players through recent seasons being key to their reaching this year's UCL decider against Liverpool.
"After my time there, they sold Modric, they sold Bale, Tottenham were a selling team, clearly," he said. "But they have grown a lot -- with a new stadium and new training ground. And Pochettino has managed to persuade Levy to keep hold of all his best players. They are now one of the best teams in Europe."