Koeman was the coach of the central midfielder for the Netherlands international side and gave De Jong advise on moving to the Camp Nou from Ajax in the summer of 2019.
Koeman had previously been a playing legend at the Blaugrana and also a prominent member of the coaching staff, so he was one of the best placed individuals to recommend the club to the Dutch national star.
However, he did give De Jong a word of warning that he would need discipline in the city, so high was the standard of living in the Catalan capital.
“Ronald Koeman told me to be careful in Barcelona because life is very good,” De Jong told an interview with UEFA, as per Marca.
“I spoke with him (on the phone more than a year ago) and he was very positive about Barcelona as a club and also about Barcelona as a city.
“So what he told me was almost all positive. He explained to me that I had to be careful, that I shouldn’t go to restaurants too much or eat too much because life in Barcelona is very good and sometimes you feel like you’re on holiday all year.
“He just told me: ‘Be careful with that and, otherwise, everything is very good.’ In the end, football is the most important thing.
“Life in Barcelona is very comfortable. It is very good because the climate is really good, better than in the Netherlands. We have the beach, we have the mountains and people are really nice to me. I am enjoying life in Barcelona a lot.”
De Jong has become a crucial figure for Barcelona across three coaches – Ernesto Valverde, Quique Setien and Koeman – and recently penned a new long-term contract at the club.