Football teams in Europe build their squads by buying players during the summer transfer window, which fascinates football fans across the world. Despite the coronavirus epidemic, Europe's top clubs are hoping to add superstar players during the summer transfer window this year. Lionel Messi has already signed a two-year contract with PSG in Ligue 1, and Chelsea have acquired Romelu Lukaku for 115 million euros from Serie A champion (2020/2021) Inter Milan. Erling Haaland, Kylian Mbappe, Cristiano Ronaldo, Harry Kane, and Kylian Mbappe are all available for a new challenge. Let's look at some of the latest summer football transfer news in 2021. Transfer Rumours: Potential Transfers Before the Deadline Kylian Mbappe PSG signed one of the greatest ever footballers, Lionel Messi earlier this month with the aim of creating a strong attacking line-up in Europe with Neymar, Mbappe, and Messi upfront. However, their wish may not be fulfilled because Mbappe has reportedly declined to extend his current deal with the Paris-Saint Germain. Read: Argentina to Face Brazil in FIFA World Cup 2022 Qualifiers According to rumors, he is considering leaving the club for Real Madrid this summer. He has also no worries about finishing his current contract, which will expire at the end of the 2021/2022 season. Real Madrid have officially made a 160 million euro offer to PSG to lure Mbappe to the Santiago Bernabéu. PSG's Director of Football, Leonardo, has confirmed that he would not be sold for a low price. Various reports claim, any team interested in acquiring Mbappe this season will have to pay 220 million euros. In the coming days, this Mbappe transfer saga may take some unexpected twists. Cristiano Ronaldo The agent for Cristiano Ronaldo, Jorge Mendes is now working on a transfer for his client. Ronaldo may be forced to finish his present deal with Juventus if he cannot find a suitable club. Earlier, PSG had expressed interest in luring Cristiano Ronaldo if Mbappe left the club. However, according to recent rumors, Paris Saint-Germain are no longer interested in purchasing him this summer. Read: Lionel Messi signs 2-year contract with Paris Saint-Germain So, Cristiano Ronaldo's only feasible alternative would be to join Manchester City. If he departs Juventus for Manchester City, it would be a huge shock to Manchester United supporters. Ronaldo established himself as a global superstar during his time with the Red Devils from 2003 until 2009. He also won his first Ballon d'or with Manchester United. As per sources, he would cost around 25 million euros, making this spectacular transfer possible. Erling Haaland Borussia Dortmund forward Erling Haaland is one of the most talked-about players in Europe right now. Since joining German club 2020, this big forward has been in excellent form. All of Europe's major teams are vying for his signature. However, Borussia Dortmund will not sell him for a low price. This summer, Haaland will cost more than150 million euros. Chelsea attempted to sign him earlier this month, but Dortmund refused to sell him. In the following season, Erling Haaland would be available at a considerably lower price. So, we may expect him to leave next summer rather than this window. Manchester City, FC Barcelona, Bayern Munich, Real Madrid, and Manchester United are the favorites to sign him next season. Read:2021 SAFF Championship: Bangladesh Seek First Title Since 2003 Robert Lewandowski Robert Lewandowski has established himself as a legend after spending more than a decade in the Bundesliga. He has set numerous Bundesliga records. He broke Gerd Muller's most goals in a single season in the 2021/2021 season. Lewandowski is eager to leave Bayern Munich in search of a new challenge. At the age of 33, he can only move to a team that badly need a striker for a limited period of time. For the time being, Manchester City appear to be the best choice for him. PSG might be an alternative if Mbappe leaves for Real Madrid. Because of his age, both Manchester City and PSG can purchase him for a low price. But one thing is certain: he will score a lot of goals wherever he goes. Harry Kane Harry Kane was keen to leave Tottenham Hotspur in search of silverware. Because he does not feel Tottenham is capable of winning a trophy. Kane was widely linked with a move to Manchester City. Man City allegedly offered Spurs 125 million pounds for Kane, but Daniel Levy, the Spurs chairman, turned down the offer. As per reports, they are seeking more than 150 million pounds.Finally, Harry Kane has confirmed that he will not leave Tottenham this summer, and he is allegedly demanding a weekly salary of £400,000 from the club. It will be interesting to see whether Man City make a January transfer window move for Harry Kane. Read:Tokyo Olympics 2020 –Brazil and Spain are Favorites to Meet in the Men’s Football Final Verdict According to the latest transfer news, some big signings might be completed before the end of the summer transfer window 2021. The window will end at midnight on August 31st, giving teams less than a week to execute their desired deal. As per the latest transfer rumors, Cristiano Ronaldo and Kylian Mbappe are the most likely to leave their present clubs for a new challenge. Their transfer will affect the equation in terms of Champions League football. So, the next few days of this transfer window are crucial for all of Europe's big clubs.