This year will be no different, with teams across Europe desperate to add big names to their squad. Which stars could still move on? Goal is here to bring you all the answers.
Although Carlo Ancelotti was adamant when asked if Sami Khedira would be staying at Real Madrid, the fact that he has just one year left on his contract and plenty of competition for a place in midfield means there will be no shortage of suitors for the Germany star.
His injury record - including a lengthy layoff last year for a torn anterior cruciate ligament - may put off interested parties, but his status at the Santiago Bernabeu will make him an enticing proposition. His experience of winning the Champions League and the World Cup will only intensify interest in his services.
Prices as low as 15 million euros have been quoted, with the likes of Arsenal and Bayern Munich said to be interested, but his hefty wage demands could prove to be a stumbling block.
Barcelona's decision to sign Alex Song two years ago looks more and more puzzling with each passing day, and though there might be trouble drumming up interest, the Catalans would be happy to sell him this summer, given their new acquisitions at center back and their wealth of talent in midfield.
The Cameroonian does boast extensive experience in the Premier League and guarantees a knowledge of the physical side of the game, but his time at Camp Nou, where he failed to impress, may put off any suitors.
With Monaco having already sold James Rodriguez this summer, another big name Colombian star signed last year may be the next to leave Stade Louis II.
Real Madrid long has been credited with an interest in his services and may want an alternative to Karim Benzema up front, while there have also been rumors of interest from Serie A champion Juventus in recent days.
The former Atletico Madrid star brings with him a guarantee of goals - he already has scored twice in Ligue 1 this season, and arguably deserves a better club than Monaco. A loan move seems the most likely eventuality, with a €20m price regularly quoted to take the 28-year-old for a year.
After flattering to deceive and playing largely out of position during his first season at Paris Saint-Germain, rumors of a move away from Ligue 1 have never truly left Edinson Cavani.
The Uruguayan says he is happy to stay put for now and the club will have no intention of selling him, with Zlatan Ibrahimovic sidelined and approaching 33.
Liverpool was rebuffed in its advances for the former Napoli man earlier in the summer, but the injury sustained by Olivier Giroud has prompted speculation that Arsenal could launch an audacious €62 million bid for him.
The spate of big-name signings in recent years has left Paris Saint-Germain youngster Adrien Rabiot's chances of breaking into the first team few and far between and the talented midfielder could leave the French capital this summer in search of regular playing time.
An able passer of the ball with a hefty frame to boot, the 19-year-old is capable of doing a job in both halves for any team that signs him, with Arsenal, Juventus, AC Milan and Roma all said to be monitoring him.
It is unclear whether his club regards him as available for transfer, but the precocious teenager looks to have a big career ahead of him.
Having been pushed out of the Chelsea first team by Thibaut Courtois this summer, Jose Mourinho has admitted that Petr Cech is unhappy with his situation at Stamford Bridge, and there would be no shortage of suitors for the Czech goalkeeper's services.
He has been with his current employers a decade now, winning a host of titles during his time at west London, including the Champions League, in which he was the penalty-saving hero in the final.
At 32, he has more than a few good years left in him and has intimated that he would not like to stay put to be second choice. Paris Saint-Germain and Real Madrid are both said to be interested and, given his new status as a squad player, he may be available for around €12m.
The arrivals of Didier Drogba and Diego Costa at Stamford Bridge this summer have pushed Fernando Torres to third choice striker at Chelsea, something the Spain international will undoubtedly be unhappy about.
Now 30, his best years are firmly behind him and with his stock having fallen to the level where he could be considered a bargain, he could prove to be good cover for a team needing to bolster its front line and AC Milan, Liverpool and Valencia are among the teams to have been linked with his services.
However, despite the Spaniard's low asking price and exerpience in both club and international football, many teams may consider him to be damaged goods and would be unwilling to meet his wage demands. Milan CEO Adriano Galliani has confirmed the Serie A side's interest, but it may only move for a loan deal.
Though Lukas Podolski looked certain to leave Arsenal just a few days ago, the injury to Olivier Giroud has thrown his exit into doubt. The Gunners may still be tempted to cash in if a suitable offer arrives for the Germany star's services, though they would want to make a profit on the €12m they spent on him at this stage.
The former Koln man has always been on the fringes at the Emirates Stadium because of questions about his work rate, but he has a happy knack of finding the target thanks to his lethal finishing and smart positioning.
Wolfsburg and Juventus are among the teams to have been most heavily linked with a move for the Poland-born attacker, but Giroud's injury may ensure that he stays put.
Barcelona wants Juan Cuadrado. Juan Cuadrado wants Barcelona. The only problem is that Fiorentina does not want to sell the Colombian. At least, not now.
Viola president Andrea Dalle Valle admitted earlier this month that the player would be granted his wish to leave the Artemio Franchi - as long as the club's asking price (believed to be in the region of €40m) was met.
However, the news that Giuseppe Rossi is again being troubled by his right knee has changed everything, as Fiorentina now has little interest in losing one talented attacker while there are serious doubts over the fitness of another – particularly on the eve of the new Serie A season.
Speculation about Arturo Vidal's future simply refuses to disappear, and though Juventus has been steadfast in its insistence that the Chilean will not be leaving Turin, there is still a possibility that he may sign with another club before the end of the transfer window.
The former Bayer Leverkusen man has developed into one of the world's finest midfielders during his time in Serie A and is a proven performer at the top level, bringing with him a guarantee of goals, tireless running and outstanding play in both halves.
Manchester United remains the most likely destination for the 27-year-old but reportedly has worries about his fitness. The last price listed for the Santiago native was merely €42.5m - a paltry amount for the quality that he provides.
|RAFAEL VAN DER VAART
After flirting perilously close to relegation last year, Hamburg has to rebuild so it does not slip into the 2. Bundesliga for the first time in its history, and Rafael van der Vaart may be the biggest casualty.
Signed two years ago from Tottenham, the Dutchman commands a hefty salary which HSV is eager to cut from its wage bill, while the club already has sounded out Lewis Holtby as a potential replacement for the attacking midfielder.
Trabzonspor is known to be interested in the Netherlands international, who brings with him a wealth of experience at international and club level.