The 13-time European champions, Real Madrid, are arguably the most ambitious club in the history of the sport. They are seldom satisfied with their achievements and are always desperate to win more. In pursuit of excellence, they have had the privilege of fielding some of the best players in history. However, the big-money moves have often come at a cost. They have had to unload players who deserved to stay a little longer.Today, we take a look at players Real Madrid sold prematurely and later regretted their decision. Now, without standing at the ceremony, let's get to it.Special mention: Angel di Maria, Sami Khedira, Gonzalo Higuain.#5 Marcos Llorente (Sold to Atletico Madrid)Leganes v Real Madrid - Spanish Copa del ReyUnlike others on this list, Marcos Llorente has not yet done anything of massive significance in his career. But that should not sway us from the fact that Real Madrid should have figured out a way to hold on to the versatile midfielder.Marcos Llorente came up through Real Madrid’s youth system and was meant to be a part of the first team. Unfortunately, Real Madrid had Casemiro, Luka Modric, and Toni Kroos as their preferred midfield trio, which made it impossible for Llorente to break in.After his stunning stint at Alaves, Real Madrid recalled the player from loan in 2017. Sadly, he could only make 20 appearances over the course of the 2017-18 season. In 2018-19, the number of appearances decreased to 16, which ultimately contributed to his transfer in 2019.Marcos Llorente: Only Sergio Alvarez (143) made more tackles than @marcosllorente (122) in the 2016/17 LaLiga season#TBTFor more player stats -- https://t.co/sHUPA8P55U pic.twitter.com/5SJjzSDTwv— WhoScored.com (@WhoScored) June 20, 2019Real Madrid sold the player to Atletico Madrid for €18million. A season later, Atletico won La Liga, beating Real Madrid and Barcelona. Unsurprisingly, he was one of Atletico’s best players in the 2020-21 season, registering 12 goals and 11 assists in La Liga itself.#4 Mesut Ozil (Sold to Arsenal)Ajax Amsterdam v Real Madrid - UEFA Champions LeagueAsk any Real Madrid fan to pick their favorite playmaker, and they will unhesitantly point at Mesut Ozil. The German was part of a group of youngsters that impressed in the 2010 World Cup, and Real Madrid were quick to pull the trigger. Los Blancos signed the player from Werder Bremen in 2010 for only €18million, which seems ludicrous in this day and age.Ozil, alongside Angel Di Maria and Sami Khedira, formed Real Madrid's new midfield core. The trio paid dividends in some of the most crucial spells of the club’s history.Watching some old Madrid clips right now… Ronaldo and Ozil’s on field connection was second to none. It’s like they were being controlled by the same person, literally perfect. Where to be, what to do, how to do it, PERFECT. Unreal duo.— M.🐐 (@MikhaeIII) September 6, 2021Ozil’s telepathic connection with Cristiano Ronaldo became Real Madrid’s biggest strength, as the duo could breach any defense in the world without breaking a sweat. Ozil provided 80 assists and scored 29 goals between 2010 and 2013 before being sold to Arsenal for around €50 million. He currently plies his trade at Turkish club Fenerbahce.