The former Uruguay striker briefly spent time with the Belgian goalkeeper during the formative days of his career at Atletico Madrid back in 2011.
Forlan was impressed by the way Courtois, 24, adjusted to life in Spain before returning to Stamford Bridge and becoming one of the best keeper’s in the world.
“He was new and on loan from Chelsea, very pleasant and very shy. I left for Inter Milan, he stayed and had a superb loan spell at Atletico, where he played in the team which knocked Chelsea out of the 2014 Champions League.
“A few months after I left Atletico, I was surprised to see an interview with Courtois where he spoke really good Spanish, with all the correct pronunciation, which is not easy for any player new to a country, not because they do not want to learn but because it is not an easy language to learn.
“I still had friends at Atletico and they told me he was dating a Spanish girl. That is the best way to learn a language quickly.