3) Yerry Mina
In January 2018, Barcelona made an even more ineffective signing in the young defender Yerry Mina Signed from Palmeiras for 11.8 million euros.
The Colombian centre back made just 1 appearance in his first 3 months at the Camp Nou. Clearly not ready to step up to the expectations of him at the Blaugrana, Mina eventually reentered the side amid the injury crises at the back end of the season.
With the league title already wrapped up, he was given a rare start against Levante in La Liga who won 5-4 to give the Blaugrana their only defeat in La Liga that season with Mina's performance full of defensive errors.
Despite having an impressive World Cup for Colombia, the 23-year-old was unhappy at Catalonia and Barcelona eventually decided to sell him to Everton for a tasty 20 million Euro profit.