On January 25, City splashed out on Echeverri from River Plate in a deal worth £12.5million plus add-ons.
The 18-year-old has been loaned back to the Argentine side to continue his development while City's announcement was picked up on by eagle-eyed fans.
On City's official Spanish-speaking X account, they made the announcement of the signing from River at a very specific time.
After a post was made at 9:12 in the morning, it did not take long for some to decipher that it was a reference to the Copa Libertadores final of 2018.
Using the time as a date, it calls back to December 9 in 2018 when River Plate beat massive rivals Boca Juniors 3-1 in the second leg of the final.
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It saw River emerge 5-3 victors on aggregate after the first leg finished 2-2.
That might be one way to win over some new supporters in Argentina after pinching one of their best up and coming talents.
Echeverri will spend the rest of the season at River on loan after signing for City earlier this month.
The youngster has been earmarked as a potential superstar in the future and can play on the left or in attacking midfield.
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He has also earned the nickname El Diablito, which means little devil in Spanish, and is a homage to his near-namesake Marco Etcheverry.
The Bolivian is often called the best player ever to hail from the South American country and there are some clear comparisons between the two.
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Like Etcheverry, the new City star is renowned for his dribbling, pace and powerful shot.
The youngster is the first signing at the Etihad this January while not much more business is expected from the Premier League champions this month.