The 2021 summer transfer window runs from approximately June 9 to August 31 and has so far been filled with multiple doses of shock and awe. However, the open season also left many wanting more, as it remains unclear just where some players may land.

With the futures of some heavy hitters cemented for the upcoming football seasons, the jury is still out on what may happen with a few star players, especially when it comes to football sensation Kylian Mbappe.

From football greats Lionel Messi to Cristiano Ronaldo, the open season has had a good serving of epic transfers to keep the football world on its toes. But now, with speculation rising that Mbappe may leave France’s Paris-Saint Germain, it’s anyone’s guess what developments may emerge over the next four days of the 2021 'silly season'. 

Let’s take a look at one of the more hair-raising, electric transfers to date for this year’s transfer window.

Cristiano Ronaldo

After weeks of speculation running high, it was confirmed on Friday that famed Portuguese forward Cristiano Ronaldo would officially be suiting up with Manchester United again after having spent years with Real Madrid and Juventus.

In a statement released by the English club, officials recalled CR7’s accolades and how Ronaldo scored some 118 goals over 292 games during his initial six-year run with Man U.

“Everyone at the club looks forward to welcoming Cristiano back to Manchester,” reads the statement, which notes that the transfer agreement made with Juventus is subject to “personal terms, visa and medical.”

The somewhat surprising announcement came exactly 10 days after Ronaldo took to social media as part of an effort to silence chatter surrounding his potential shift away from the Turin-based Italian football club.

“There have been frequent news and stories associating me with a number of clubs in many different leagues, with nobody ever being concerned about trying to find out the actual truth,” he stated in an Instagram post.

“I’m breaking my silence now to say that I can’t allow people to keep playing around with my name. I remain focused on my career and in my work, committed and prepared for all the challenges that I have to face. Everything else? Everything else is just talk.”

At the time, the hype consuming the Ronaldo name was reaching an all-time high as his contract with Juventus was inching closer to its mid-2022 expiration date. Speculation also suggested that the Portuguese player could go back to Real Madrid, but those claims were quickly shot down by Carlo Ancelotti, the manager of Los Merengues.

Lionel Messi

The most shocking transfer of the 2021 silly season was by the GOAT of football - Argentine star Lionel Messi, affectionately nicknamed “La Pulga” by Spanish-speaking fans.

Messi’s heart-stopping, eyebrow-raising jump to France’s Paris-Saint Germain football club took many by surprise, as it also meant that he would no longer be with FC Barcelona, the iconic team he has captained and played for almost two decades since his 2003 debut.

After the shock announcement that he would not be renewing his contract with Barca as a result of “financial and structural obstacles,” the rumor mill went crazy speculating where the world-class forward player would hang his cleats. 

At the time, it was said that Messi could only either go to Manchester City or PSG, as the pair of clubs were the only to have enough funds to afford the player. After Man City announced that they would not be pursuing Messi, all signs pointed to PSG, which eventually confirmed the move on August 10.

​While a multitude of tears were shed at Messi’s farewell presser in Barca - some of which were dried away with a tissue that later hit the auction block, the Argentine has remained positive of his future.

"I know how talented the squad and the coaching staff are here,” Messi said in an earlier statement. “I am determined to help build something special for the club and the fans, and I am looking forward to stepping out onto the pitch at the Parc des Princes.”

Talk of Messi parting ways from Barcelona initially surfaced in August 2020 but was held off after it was revealed that La Pulga had passed the grace period in which he was allowed to break his contract. His contract with PSG is said to be worth tens of millions of euros.

Sergio Ramos

Real Madrid fan favorite Sergio Ramos hopped off the Merengues roster in early July in favor of Paris-Saint Germain, after his 16th season with the Spanish club ended without obtaining the two-year contract he had requested.

It’s worth noting that Real Madrid’s unwritten rule is to only issue one-year contract extensions for any player over 30 years of age. Ramos, who helped the team win a bevy of awards - including four UEFA Champions League trophies, is 35 years old. He had been with the team since 2005.

“This is a big change in my life, a new challenge and it is a day I will never forget,” Ramos said in a July statement. “I am very proud to be a part of this ambitious project, to be a part of this squad with so many great players.”

“PSG is a club that has already proven itself at the highest level. I want to continue to grow and improve at Paris and help the team to win as many trophies as possible," he added.

Completing a two-year contract on a free transfer to PSG, the versatile defender will be staying with the Princes until at least 2023. It was previously reported that Ramos was first approached about jumping to PSG in January, just seven months before the agreement was signed.

Unlike Messi, who had to give up his no.10 jersey in favor of no.30, Ramos will continue to rock his no.4 shirt with PSG.

Jack Grealish

Ahead of both the Messi and Ronaldo announcements came to the revelation that Aston Villa’s Jack Grealish would sign with Manchester City, a move that went on to cement one of the more expensive transfers in the Premier League to date.

To obtain Grealish, who had become an even more well-known player on the global stage after representing England in the Euro 2021 final, Manchester City submitted a costly offer that activated a £100 million release clause listed under the player’s Aston Villa contract.

“I am incredibly happy to have joined Manchester City,” Grealish said in a statement accompanying a club release. “City are the best team in the country with a manager considered to be the best in the world – it’s a dream come true to be part of this club.”

Prior to the early August transfer payout, the highest fee in the Premier League was £93.25 million, paid by Manchester United to Juventus in 2016 for French midfielder Paul Pogba.

Grealish’s contract is set to last for approximately six years. Interestingly, he made his debut with Aston Villa in 2014 in a game against Man City.

Romelu Lukak

After spending 10 years away, Belgian player Romelu Lukaku made his own shock return to the Premier League’s Chelsea organization, to the tune of a tear-inducing £97.5 million. 

While the switch from Italy’s Inter Milan to Chelsea has not been warmly received by fans of either team, Lukaku’s jump to the Blues is sure to see the English club add some new trophies to its shelves. The 28-year-old Belgian helped Inter Milan gain its latest Serie A title.

Lukaku’s contract with Chelsea is expected to last at least five years. The payout for Lukaku’s transfer marks him as one of the top 10 most expensive players in the history of the sport.

The decorated player’s previous stint with Chelsea ranged from 2011 to 2014, and saw him make at least 10 appearances during that time period. He was later forfeited to Everton for a paltry £28 million, before eventually being forked over to Manchester United in 2017 and later to Inter Milan in 2019.

Gianluigi Buffon

And then there was Gianluigi Buffon, the veteran Italian goalkeeper who has defied goalie standards and trash talk of retiring, now that he is a mere 43 years young.

While many believed that he would throw in the towel after wrapping with Juventus, he made the head-spinning announcement that he would retrace his steps and return to the Parma Calcio 1913 club.

Returning to his boyhood club, Parma announced the homecoming of their “superman” with a video that depicted Gigi digging what appears to be a time capsule buried underneath one of the nets at the Stadio Ennio Tardini.

Buffon made his debut with the club in November 1995, just 17. He had been one of many players to come out of the Ducali youth academy.

Ahead of the announcement, rumors emerged that Buffon could retire, go to FC Barcelona, or even head over to Brazil’s Flamengo club after he called it quits with Juventus.

The contract is expected to last for a period of two years. Currently listed as a Serie B team, officials are hoping to bump up the club with the treasured goalie’s grand return.