There are plenty of other big names out of contract and being touted for moves, including the likes of Manchester United's David De Gea, Juventus' Adrien Rabiot, Real Madrid's Marco Asensio and Inter Milan's Milan Skriniar to name just a few.
Still, how does the current crop compare to some of the biggest free transfers in modern football history? Flashscore has picked out 10 of the biggest freebies from recent times:
James Milner: Manchester City > Liverpool
'Boring Milner' has a trophy cabinet and winning pedigree relatively unrivalled in English football. After winning the Premier League twice, an FA Cup, a League Cup and Community Shield during his five-year spell at Manchester City, Milner became one of Jurgen Klopp's first signings upon his arrival at Anfield.
Milner's durability and positional flexibility made him a trusted cog in the German's Liverpool machine, and making another free transfer move to Brighton during the current summer window, Milner had added another league title, FA Cup, League Cup and Community Shield plus a Champions League, Super Cup and Club World Cup to his collection.
Robert Lewandowski: Borussia Dortmund > Bayern Munich
After bailing out Dortmund from financial ruin in the mid-2000s, Bayern made the most of their 'gentleman's agreement' by snapping up BVB's prized asset in Polish superstar Lewandowski.
Lewy had scored 103 goals in 187 Dortmund appearances, winning two Bundesliga titles and both domestic cups.
A tasty return of 344 goals in 375 games in Munich saw the striker waltz his way through even more of German football's trophy list, as well as adding a Champions League title to boot.
David Alaba: Bayern Munich > Real Madrid
Ten Bundesliga titles, two Champions Leagues and two Club World Cups were apparently enough for the Austrian utility player as he ventured off to sunny Spain in 2021.
Things haven't slowed down too much, with the skilled midfielder/wing-back/centre-back adding a La Liga crown and more European triumphs to his name since. David's gonna need a bigger trophy cabinet.
Andrea Pirlo: AC Milan > Juventus
Milan strangely assumed the magician was well past his best by the time they let Andrea Pirlo go at the end of the 2010/11 season. The midfield architect had spent 11 seasons at the red side of the San Siro but struggled for game time under Massimiliano Allegri in his final season, and made the surprising decision to switch to Juventus.
Upon learning of the move, compatriot Gianluigi Buffon declared the imminent free transfer as "the singing of the century". It didn't turn out too bad, with the 32-year-old still putting in four elite-level seasons during his time in Turin, winning the Serie A title in each year and narrowly missing out on Champions League glory.
Jay Jay Okocha: PSG > Bolton
PSG had paid around £14 million for Okocha in 1998, making him the most expensive African player in history at that time. But, while easy on the eye and allegedly playing a key role in the development of a young Ronaldinho, Okocha was hit-and-miss in Paris, notching just 12 goals in 84 matches during his four-year spell there.
There aren't many out there who would see an opportunity in the switch from glamorous Paris to, well, Bolton, but Jay Jay did. He swiftly became a huge hit amongst fans of all clubs in England - "so good they named him twice" being the key line during his time in Greater Manchester - with the Nigerian quickly finding his feet, scoring some cracking goals and going on to cement himself as a Premier League legend still fondly remembered today.
Sol Campbell: Tottenham > Arsenal
Time to skip to the next one, Spurs fans. Sol Campbell made the unholiest of North London decisions after switching from Tottenham to Arsenal in the summer of 2001 for absolutely no fee at all.
Still known as 'Judas' on the Tottenham terraces to this day, some ugly scenes and chants have followed the move ever since in what ultimately proved to be one of the nastiest and most memorable free transfers to ever occur.
He claims to still feel vindicated by his decision in spite of the hatred, though, and who can blame him? After a solitary League Cup win during his Spurs years, Campbell went on to win three FA Cups, a Community Shield, and two Premier League titles - including playing a key role as part of the famous invincibles.
Michael Ballack: Bayern Munich > Chelsea
Coming off the back of three straight Bundesliga championships and three straight German Player of the Year awards, it's safe to say Bayern weren't best pleased to see Ballack shipped off for zilch in 2006.
The powerful, commanding midfielder is still revered by Chelsea fans as one of their greatest-ever signings and underrated Premier League players.
During a successful spell in the club's history under Carlo Ancelotti, Ballack won a Premier League medal, three FA Cups, a League Cup and a Community Shield, before heading home to Bayer Leverkusen in 2010.
Zlatan Ibrahimovic: PSG > Manchester United
The man, the myth, the legend; Zlatan finally made his way to English shores to ply his trade in what many felt at the time was more of a PR job than a serious acquisition.
Arriving at Old Trafford in 2016 from PSG, the 34-year-old was handed the number nine jersey ahead of the 2016/17 season under Jose Mourinho. He immediately netted the winner in the Community Shield match against Leicester and went on to bag an impressive 17 goals in his first season with the club.
Injuries hampered his second season before he headed off to MLS, but he left with Europa League and League Cup winner's medal in his pocket, as well as a newfound appreciation from football fans in Britain.
Paul Pogba: Manchester United > Juventus
Seen as one of the few glaring mistakes made by the inimitable Sir Alex Ferguson at Manchester United, in 2012 a blossoming Paul Pogba - feeling like he wasn't receiving the first-time opportunities he felt he deserved - wound down his contract and stuck two fingers up at his former boss before heading to Juventus.
The move proved to be a sensational one as the young Frenchman went on to become one of the world's best midfielders, at least at the time.
Pogba won four Serie A titles, two Coppa Italias and a Supercoppa Italiana during that first stint at Juve before a remarkably expensive turn of events saw Manchester United re-buy him for an eye-watering £89 million, then a world record fee.
While he picked up a couple of domestic cups and even won a World Cup during that time, Pogba never got close to hitting the heights expected of him upon his Old Trafford return and has now ended up back at Juventus yet again.
Lionel Messi: Barcelona > PSG
Messi was brought to tears in his final press conference at Barcelona. Having spent the majority of his life at the Catalan club, he was effectively forced to leave as Barça fell deeper into a financial spiral that ultimately led them into taking some huge risks on their own futures.
There weren't many clubs that could afford the weight of the Argentine's wages, but PSG were one of them.
While he didn't exactly live up to his stellar reputation during his two seasons in the French capital, he still notched up 32 goals in 75 appearances and showed off some of the magic that makes him arguably the greatest player we've ever seen.
Now off to Miami on another free transfer, it's a little bit crazy to think a potential GOAT like Messi has switched clubs twice yet never once commanded a transfer fee.
