Barcelona are already preparing for the summer window after finishing third in La Liga in the 2020-21 season. The Catalans watched their former player Luis Suarez power Atletico Madrid to the title and will have rued the decision to let the Uruguayan leave. They are ready to make amends, however, with reports surfacing that Sergio Aguero is close to a move to the Camp Nou.Barcelona could make major changes to the squad over the summer, with various positions in the team requiring reinforcements. The Catalans are also sweating on the future of Lionel Messi although the Argentinean is widely expected to stay at the club beyond the summer.On that note, let’s take a look at the top transfer stories for Barcelona on 26 May 2021.Barcelona looking for replacement for Ronald KoemanRonald KoemanAccording to Marca via TV3, Barcelona president Joan Laporta has informed Ronald Koeman that he is looking for a replacement for the Dutchman. Laporta reportedly informed Koeman of his decision in a meeting held on Tuesday. Koeman’s time at Camp Nou has not been too impressive. In addition to faltering in the La Liga, Barcelona also exited the Champions League in the Round of 16 this season.The Catalans finished as runners-up in the Supercopa de Espana but did manage to win the Copa Del Rey. If the Dutchman does end up leaving, it is not yet clear who the Catalans are targeting as a replacement.Premier League star set to join BarcelonaGeorginio WijnaldumAcclaimed sports journalist Fabrizio Romano has confirmed that Liverpool star Georginio Wijnaldum is all set to join Barcelona. The Dutchman has become a pivotal part of Jurgen Klopp’s team at Anfield in recent times. However, the German manager failed to convince Wijnaldum to extend his stay at the club, as he preferred to run down his contract and leave Liverpool as a free agent.Gini Wijnaldum to Barcelona, confirmed and here we go! 🔴🔵 #FCBThe verbal agreement has been reached, Wijnaldum is joining Barça until June 2024. He’s expected to sign his contract in the next few days - work in progress to complete the deal reducing Gini’s salary. ⏳ https://t.co/TlqznhJfBh— Fabrizio Romano (@FabrizioRomano) May 26, 2021The Dutchman has reportedly reached a verbal agreement with the Catalans and will put pen to paper on a contract in the coming days.Final negotiations regarding the player’s salary are currently taking place, with Wijnaldum expected to take a pay cut to join Barcelona. The Dutchman will sign a deal that will see him stay at Camp Nou until the summer of 2024.Barcelona eyeing move for Crystal Palace starAccording to The Hard Tackles, Barcelona are eyeing a move for Crystal Palace’s Patrick van Aanholt. The player's current contract with the Premier League side is set to expire this summer. The Dutchman is among a host of free agents the Catalans are targeting at the moment, with Sergio Aguero, Eric Garcia and Wijnaldum also on their shopping list ahead of next season. Barcelona could sign all four of these players for free this summer 👀 pic.twitter.com/HO25oKMRUB— Goal (@goal) May 26, 2021Van Aanholt has suffered due to a shoulder injury this season but has been impressive for the Eagles since joining them in 2017. The 30-year-old, however, has managed just 23 appearances this season. At this point in time, the move does represent a degree of risk for Barcelona.