Not all successful transfers have to involve large sums of money.
Numerous top-class footballers have moved on to greener pastures and carved out more success for themselves and their new clubs after completing free transfers.
Here are five shining examples.
🇮🇹 Andrea Pirlo
Milan ✈️ Juventus
By the end of the 2010-11 season at AC Milan, the long-haired playmaker found himself out of favour at the San Siro after a long-term injury. The Rossoneri board offered Pirlo a one-year contract extension but the Italian was looking for a three-year deal. Juventus snapped him up and it was one of the smartest transfer moves they've ever made. Pirlo won four consecutive Serie A titles and an additional three domestic cups with the Old Lady before a move to the MLS in 2015. The elegant schemer's experience and know-how of winning the World Cup and UEFA Champions League are traits that money just can't buy.
🇵🇱 Robert Lewandowski
Borussia Dortmund ✈️ Bayern
In 2014, Polish goal-machine Robert Lewandowski crossed the great divide from Borussia Dortmund to Bayern Munich. Mario Götze had already made the same switch to the tune of €37m a year before, but it was Lewandowski's move that really rubbed salt into the wounds. His numbers are ridiculous; he has scored 242 goals in 285 Bayern Munich appearances. The 31-year-old will go down as one of the finest strikers of his generation, which is incredible if you consider that he didn't cost the Bavarians a cent.
🏴 Sol Campbell
Tottenham ✈️ Arsenal
Arsenal legend Sol Campbell's bitterly controversial move from Tottenham simultaneously goes down as one of the shrewdest and most unpopular pieces of business in Premier League history. Campbell came through the ranks at Spurs, spending 12 years at White Hart Lane, only to leave for their North London archrivals on a free transfer. All of the controversies aside, Campbell won two Premier League titles and three FA Cup winner's medals with Arsene Wenger's Arsenal, vindicating his decision. The Gunners famously won the Premier League without tasting a single defeat in 2003-04, and the world-class defensive capabilities of Sol Campbell were a cornerstone of that success.
🇦🇷 Esteban Cambiasso
Real Madrid ✈️ Inter ✈️ Leicester
Real Madrid would love to turn back time on a few of their puzzling transfer decisions in the early 2000s, especially when it comes to defensive midfielders. First, it was Claude Makélélé in 2003 and then a year later, they let Esteban Cambiasso leave the Bernabéu on a free transfer. Madrid's loss was Inter Milan's gain as the Argentine became the heartbeat of an Inter team that won five Serie A titles and the treble in 2010 under Jose Mourinho. After a decade at Inter, Cambiasso moved to Leicester City, again on a free, helping them avoid relegation in 2015.
🏴 James Milner
Man City ✈️ Liverpool
It feels as though James Milner has been around forever. 18 years ago, he made his Premier League debut for Leeds United and he's been a vital cog in every single team he has represented ever since. Milner's versatility has sometimes seen him play more of the role of a substitute but he always delivers when called upon. He has been a widely-respected figure in the dressing rooms at Leeds, Newcastle, Aston Villa, Man City and most recently with European and English Champions Liverpool. Since moving to Anfield for free in 2015, his experience has been invaluable to Jürgen Klopp, with Milner proving that he's Mr Reliable, no matter how big the occasion. He's now a three-time Premier League winner.
Who do you think is the best free transfer of all time?