10 footballers who never fulfilled their potential

#3 - Adriano:

Adriano vs Sampdoria - Serie A

When asked about the biggest regret in his professional career, former Internazionale captain Javier Zanetti's answer was very touching.

What Zanetti regrets the most was seeing Adriano's career being ruined, without being able to do anything about it. After two spectacular seasons at Parma, Inter resigned Adriano in 2004, at the age of 22. The Brazilian was already one of the best players in the league, and was being touted as the new Ronaldo.

Adriano led Brazil to Copa América 2004 triumph ending up as top scorer and best player, after scoring a miraculous last-moment goal against Argentina in the final, which led to penalties, where Brazil emerged victorious.

In 2005, Adriano was again the number one star for Brazil, ending up as top scorer and best player of the Confederations Cup, after single-handedly demolishing Germany in the semi finals, and playing a big role in crushing Argentina 4-1 in the final game.

At that moment, even Ronaldo himself picked Adriano as his successor for the famous 'camisa nove' shirt. But what happened next? The rising striker's father died, and people close to Adriano revealed that he moaned his death, and was not able to recover.

The Brazilian left Inter back to Brazil where he started drinking and partying nonstop. However, Adriano signed for Carioca giants Flamengo in 2009, and he was again the best player and the top scorer in a competition that he won, this time the Brazilian league.

And that's about it. From that moment, Adriano totally gave up on football and did not even bother showing up for training anymore.

#2 - Denilson:

Denislon vs Valencia - La Liga

When football fans across the globe talk about unfulfilled potential, Denilson is usually one of the most common examples that comes to mind. The Brazilian was blessed with phenomenal dribbling skills, and incredible acceleration to pull his way past defenders.

At his best, Denilson seemed unstoppable and the opponents often gathered against him in numbers in order to figure out a way to contain him. In 1998, he joined Real Betis at the age of 21, for $43 million, which was the world-record at that time.

Despite winning the Copa del Rey in 2005, Denilson's end product was too poor and he never justified the crazy sum that Betis paid for him.

His subsequent spells at club football did not impress too much either. However, in his early days, Denilson basically won it all with Brazil's national team: the Confederations Cup and Copa América in 1997, and the FIFA World Cup in 2002, where he played the role of a super sub, who would come on to humiliate the defenders for the spectacle.

The fact that Denilson's last Brazil call-up came at the age of 25, helps you understand how quickly his career went downhill. Having won it all with Brazil, you'd expect that he'd still make the squad later on, as an experienced player - but no, the coaches did not even deem him good enough for this mission.