Sometimes football scouts and managers get it horribly, horribly wrong. Here are the most famous examples of superstar players who slipped the net.
LUIS SUAREZ (2010, TOTTENHAM HOTSPUR)
During Tottenham's miserable defeat by Liverpool last Sunday, Spurs boss Tim Sherwood sat stony faced in the stands instead of hollering out instructions from the technical area, prompting the club's travelling fans to sing: "Where is our manager, where is our manager?"
They should be thankful Sherwood wasn't on a scouting mission, judging by his decision not to sign Luis Suarez from Ajax a few years ago.
Dutch legend Ruud Gullit told the Daily Mail newspaper: "I met Sherwood together with Les Ferdinand, they were Harry Redknapp's assistants and also his scouts. They asked me all kinds of questions about Suarez, so I just point blank said, 'You have to snap him up, without any hesitation, in a heartbeat'.
"Well, we're not sure," they said while they actually watched him play. That was a huge mistake.
2013-14 EPL goals: Luis Suarez 29. Roberto Soldado 6.
GARETH BALE (2006, Arsenal)
When Arsene Wenger signed boy wonder Theo Walcott from Southampton in 2006, he was also offered a certain Gareth Bale as part of a double deal.
However, the Frenchman decided to pass on the future Galactico, who was then plying his trade as a left back.
"We didn't take him (Gareth Bale) as we had Ashley Cole and Gael Clichy and didn't want another left back," he told The Mirror newspaper.
"I must confess it was a huge mistake. He struggled at the start at Tottenham, then they moved him to midfield and he has done exceptionally well. The career of a player sometimes depends on playing in the right position."
CRISTIANO RONALDO (2003, LIVERPOOL)
Back in 2009, I spent a week with a Liverpool FC Legends team in Grenada, writing a magazine article about the players and a charity football match they were playing in aid of the Jason Roberts Foundation.
However, after John Barnes pulled out of the trip at the eleventh hour, Legends boss Phil Thompson was in dire need of a replacement right-winger for the match against an All-Star team at the national stadium.
He chose me! It wasn't the first time Thompson's judgment had been called into question.
Six years earlier, during his time as No. 2 to Gerard Houllier at Liverpool, the former Reds skipper was sent to Portugal to run the rule over a certain Cristiano Ronaldo, who was making a name for himself at Sporting Lisbon.
Thompson's verdict? "Too individual. Not a Liverpool player."
YAYA TOURE (2003, Arsenal)
Arsene Wenger's inability to sign the "next Patrick Vieira" wasn't a case of ineptitude on his part, just rank bad luck as passport issues scuppered the move, and he would instead sign for Shakhtar Donetsk.
Yaya's older brother, Kolo, had already made a massive impression on his first day on trial at the club 12 months previously.
In a "non-contact" small-sided game, the Ivory Coast defender managed to floor legendary icons Thierry Henry and Dennis Bergkamp with two-footed challenges.
Even Wenger became a victim.
Yaya accidentally smashed into the professor, who hobbled off and had to spend the next hour with an ice pack strapped on his damaged ankle.