Kylian Mbappe, Lionel Messi, a Spurs player to Arsenal and the all-time top 10 free transfers

Kylian Mbappe is leaving Paris Saint-Germain this summer and announced his official news last Friday ahead of his final appearance at Parc des Princes which finished with a 3-1 loss to Toulouse in Ligue 1. The France international is expected to join Real Madrid as a free agent this summer and will join the growing line of players to have left the French giants for nothing which also includes former captain Thiago Silva who joined Chelsea, talismanic strike pair Zlatan Ibrahimovic and Edinson Cavani who both left for Manchester United as well as Angel Di Maria and Adrien Rabiot who later resurfaced with Juventus.

We look at the 10 most impressive free agent signings that Mbappe will be up against in terms of proving to be value for (relatively little) money.

No. 10: Lionel Messi from Barcelona to PSG to Inter Miami

• 2x Ligue 1
• 1x Trophee des Champions
• 1x Leagues Cup

The chance to sign arguably the greatest player to ever play the game of soccer does not present itself often and it would have been rude of PSG to not take the chance after his Barcelona spell came to a painful end. Messi did not enjoy the best of times in Paris but he still won three trophies and also became a FIFA World Cup winner while playing in Ligue 1. Whatever happens, the Argentina international's time as a free agent was an unexpected development in the later part of his European career. However, it happened twice as his next move -- to Inter Miami -- came once his PSG contract expired and he switched to Major League Soccer as Les Parisiens were shedding the likes of Messi but also Neymar. Although the Rosario native only has Leagues Cup success to his name so far, that is still the Herons' first silverware of any description in club history and the impact that Messi has had on MLS cannot be understated. In terms of getting bang for buck, this U.S. chapter is working out much better for player and club than the Paris interlude.

No. 9: Cafu from Roma to Milan

• 1x Serie A
• 1x Supercoppa Italiana
• 1x UEFA Champions League
• 1x FIFA Club World Cup
• 2x UEFA Super Cup

Back in the early 2000s, Cafu was a veteran authority at right back and opted to leave AS Roma for Milan in 2003 with little in the tank -- or so they thought. The Brazil international, who won two World Cups, went on to spend five years at San Siro and won the Scudetto and the Champions League before retiring as a Rossoneri favorite.

No. 8: Sol Campbell from Tottenham Hotspur to Arsenal

• 2x Premier League
• 2x FA Cup
• 1x UCL runners-up
• 1x FA Community Shield

Few players have directly crossed the North London divide and even fewer have done so as explosively as Sol Campbell did in 2001 but few can argue with the impact that the former England international had on Arsenal at the time. One of the legendary Invincibles, he will forever be remembered as a cornerstone of Arsene Wenger's legendary Gunners side.

No. 7: Thiago Silva from PSG to Chelsea

• 1x UCL
• 1x UEFA Super Cup
• 1x Club World Cup

When Thiago Silva's time as PSG captain brutally ended with Champions League heartache against Bayern Munich in Portugal, his next move was a surprise: a free transfer to Chelsea where he would be reunited with former Parisien head coach Thomas Tuchel. Even more surprisingly is what happened next as the German inspired the Blues to that elusive UCL title with the iNFLuential Brazil international a key part of his starting XI.

No. 6: David Alaba from Bayern Munich to Real Madrid

• 2x La Liga
• 1x UCL
• 1x Copa del Rey
• 1x Supercopa de Espana
• 1x Club World Cup
• 1x UEFA Super Cup

It is relatively early days yet David Alaba has already won it all with Real Madrid and could do so again this season if Carlo Ancelotti's men win the UCL again. Although the Austria international has been injured for much of the campaign, his honors list from his Bayern Munich days is impressive but his Real trophy haul is not looking too bad either.

No. 5: Esteban Cambiasso from Real Madrid to Inter

• 5x Serie A
• 5x Coppa Italia
• 4x Supercoppa Italiana
• 1x UCL
• 1x Club World Cup

In terms of historically underrated players, Esteban Cambiasso is up there as a contender for being one of the lead candidates. Discarded by Real Madrid for essentially not being flashy enough during the Galacticos era, what followed in Milan with Inter was arguably more success than the entire Galactico project with a glut of Italian silverware as part of a dominant Nerazzurri side which was crowned with a Champions League triumph.

No. 4: James Milner from Manchester City to Liverpool

• 1x EPL
• 1x FA Cup
• 1x EFL Cup
• 1x UCL (2x runners-up)
• 1x Community Shield
• 1x UEFA Super Cup
• 1x Club World Cup

Leaving Manchester City for Liverpool, James Milner was expected to be not much more than a utility piece for the Reds but the ex-England international went on to be much more than that and morphed into a model of consistency and leadership which saw him appointed as one of the senior leadership figures under Jurgen Klopp in a glorious era for the Anfield giants.

No. 3: Andrea Pirlo from Milan to Juventus

• 4x Serie A
• 1x Coppa Italia
• 2x Supercoppa Italiana
• 1x UCL runners-up

Juventus used to have a strong reputation for mastering the free agency market and one of the two most important transfers in that era was the signing of Andrea Pirlo from Milan. The former Italy 2006 World Cup winner was seen to be on his last legs when he pitched up in Turin yet would be reborn with the Bianconeri and go on to enjoy four Scudetto successes as well as three domestic cups and a Champions League final outing, so it was little wonder Gianluigi Buffon called his Azzurri teaMMAte "the signing of the century."

No. 2: Paul Pogba from Manchester United to Juventus

• 4x Serie A
• 2x Coppa Italia
• 2x Supercoppa Italiana

Topping Pirlo was always going to be tough but Juve somehow did just that when they signed Paul Pogba on a free transfer from Manchester United in 2012 before selling him back to the Red Devils and then later re-resigning him for his disastrous current spell. That first stint, though, earned the Old Lady in excess of $112 million which is nothing short of astounding when you consider that the France international won the Serie A title four times as well as two more Coppa Italia and Supercoppa Italiana crowns.

No. 1: Robert Lewandowski from Dortmund to Bayern Munich

• 8x Bundesliga
• 3x DFB Pokal
• 5x DFL Supercup
• 1x UCL
• 1x UEFA Super Cup
• 1x Club World Cup

However, few clubs can compete with Bayern Munich's feat of pinching Robert Lewandowski from Borussia Dortmund having been BVB's star man and having tried signing him for a fee in the years before his actual 2014 move. Eight Bundesliga, three DFB Pokal, five, DFL Supercup, one Champions League, one UEFA Super Cup and one FIFA Club World Cup triumph later and the Poland international left Allianz Arena as a Bavarian legend. Without Lewandowski, Bayern might not have been as dominant as they have been up until very recently in Germany.