Seven players' managers lived with regret at having sold: Stam, Cantona, Pirlo...

A manager's success at club football often hinges on the signings he makes, but sometimes it's the players he lets go that really haunts him, as these seven cases show

Sometimes, no matter how talented a player is, a manager just can't find a place for them in the team. Maybe they don't fit the style of play, maybe they don't work hard enough in training, or maybe the manager just doesn't like them.

Whatever the reasons, here are seven players clubs have almost certainly regretted selling in the long run. Hindsight is truly a wonderful thing.

Eric Cantona

"I don't know why I love you, but I do."

Leeds fans would have said the same, but you probably shouldn't mention Cantona's name in West Yorkshire anymore.

The striker's flair, style and sheer brilliance quickly made him a cult figure at Elland Road, where he played a key role in their Premier League title victory in 1992, but a man didn't believe the hype.

"Eric likes to do what he wants when he wants - and then go fuck himself," said Leeds manager Howard Wilkinson.

Even so, his move to Manchester United came as a huge shock.

As if his 11 goals in 20 appearances so far this season weren't enough to put Leeds on notice, what happened next is no secret. Eric Cantona is a name etched forever in the history of the Premier League.

READ: Eric Cantona's story and his incredible impact on Man Utd

Jaap Stam

Europe's top defender for two consecutive years, defensive pivot to three successive Premier League titles and the famous 1999 treble, and the man who steadied the ship when prop Peter Schmeichel retired, you would have thought crazy to allow someone so important to go.

However, after just three years at Manchester United, Stam was sold to Lazio for around £16million. Was it the revealing autobiography? Was it Achilles' discreet injury? Or was it just because United needed the extra money?

The defensive colossus spent another five years playing at the highest level, almost winning a second Champions League title with AC Milan on that infamous night in Istanbul. And United struggled to fill an undeniably huge void.

"Jaap Stam was the one. Without a doubt, I made a mistake there," Ferguson said in 2007 when admitting the biggest mistake of his United career.

Andrea Pirlo

"I think he was the signing of the century," exclaimed Gianluigi Buffon when Juventus signed Italy and AC Milan star Pirlo on a free transfer in 2011.

Those at San Siro thought his career was over as he won his second Serie A title in 2011, but they had no idea what was to come.

Pirlo's performances quickly reversed with younger, more energetic midfielders such as Claudio Marchisio and Arturo Vidal around him, allowing him to sit back and do what was so fascinating to watch, pushing aside the ball left or right, forward or back, five yards or 50 yards.

Pirlo's 13 assists helped Juventus lift the Serie A trophy, with the puppeteer making 500 more assists than any other player in Italy's top flight.

His four seasons at Juventus saw them win four Italian league titles, and a Champions League final loss to Barcelona ended any dreams of a treble to complete a great spell at the top. Juve.