The beautiful game is full of moments that make your jaw drop - a piece of skill so outrageous it leaves you shaking your head in disbelief.
But for every piece of magic we witness from legends like Messi and Ronaldo, there are countless other talented players who fail to live up to their enormous promise. Some succumb to injuries, others lack the mentality, but they all share one thing - the inability to scale the dizzying heights many expected of them in their early days. Here are five players who never quite fulfilled their potential, but still make you wonder 'what if?'.
Neymar - Blessed with outrageous skills and talent from a young age, Neymar's career at Barcelona promised to take him to the heights of Messi. But an obsession with showboating tricks and diving began to overshadow his goal scoring ability. His world record transfer to PSG has not resulted in Champions League glory. At 29, injuries and a lack of killer instinct means he remains behind Messi in the shadows, rather than stepping out as the main man.
Freddy Adu - Widely touted as the American Messi, Adu was the most hyped young player on the planet as a 14-year-old. He became the youngest player to sign a professional contract in American sports aged 14. While skillful, his diminutive frame proved no match for Europe's toughest leagues. Loan spells and moves failed to spark his career into life. Now 32, his talent was never allowed to blossom on the biggest stages.
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Kerlon - Signed by AC Milan as a 16-year-old prodigy in 2003, comparisons were inevitably drawn to a young Kaka. Blessed with silky skills, he dazzled in a friendly against Barca, with rumors of a 150m euro release clause. But a lack of playing time and injuries took their toll on his mentality. Loans and mediocre spells followed before retirement at just 27. A true 'what if' tale of unfulfilled promise.
Freddy Guarin - Starting his career with success at Porto, Guarin seemed destined for great things after a big money move to Inter Milan in 2012. Powerful and aggressive, he dominated midfields with an intense playing style. But off-field issues soon derailed his progress. Faced with discipline problems and weight issues, he never built on early promise. A shadow of the player he once threatened to become.
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Mario Balotelli - No player has ever frustrated fans more than Balotelli. Rarely has a player possessed such a unique blend of talent and unpredictable temperament. At Inter and then Manchester City, he displayed genius one moment but immaturity the next. Moves to Milan and Liverpool failed to curb his tendency for misbehavior off the pitch. Now 31, his career has become a sad soap opera of unfulfilled talent, rather than the main event many predicted.
Adrian Mutu - During his time at Chelsea, Mutu looked destined for superstardom after scoring on his Premier League debut. But ongoing problems with discipline, partying and controversies soon surfaced. A positive cocaine test ended his Chelsea career and saw him banned for 7 months. Changes of scene couldn't salvage a career blighted by off-pitch distractions. The Romanian Messi was another who put happiness before hard work.
From midfield maestros who lacked consistency to forwards who spent more time in nightclubs than training, these footballers demonstrate the fragility of ability. With the right environment and application, they could have graced the grandest stages. Instead, they serve as a reminder that talent alone decides nothing and potential means nothing without production.
