Florentino Perez very rarely uses the January transfer window to bolster Real Madrid's squad as most of the club's business is conducted in the summer. But there have been several times when Los Blancos' president has got his chequebook out in the winter and some have gone on to become heroes at the Bernabeu.
Take for example, Casemiro who initially arrived on loan from Brazilian club Sao Paulo in January 2013 before signing permanently. The Brazilian midfielder went on to become one of the best holding midfielders in the world.
It will be interesting to see whether Xabi Alonso is backed in this window amid links to AZ Alkmaar midfielder Kees Smit. The recruitment team will be eager to replicate five past January signings that went on to achieve huge success in the Spanish capital.
Real Madrid's 5 best January transfers
5 - Lassana Diarra (€20 million)
Lassana Diarra made a name for himself in the Premier League with Arsenal and Chelsea before joining Portsmouth in January 2008. The Gunners may feel as though they made a mistake selling him for a mere €7 million.
A year later Madrid came calling for the French holding midfielder, paying Pompey €20 million to bring him to the Bernabeu. This came after he played a key role in the English club's FA Cup triumph.
Diarra didn't set the world alight during his time with Los Blancos but he was a workhorse who put in consistent performances. He made 116 appearances, winning the La Liga title in 2012 as well as the Copa del Rey in 2011 and the Spanish Super Cup in 2013.
The Paris-born midfielder spent three years at Madrid before joining Russian outfit Anzhi Makhachkala in the summer of 2012 for €5 million. He retired at PSG in 2019 having won the Ligue 1 title twice.
4 - Diego Lopez - (€3.5 million)
Diego Lopez returned to Madrid in January 2013 after starting his career with Los Blancos. The Spanish goalkeeper rejoined his boyhood club in a €3.5 million deal which turned out to be an absolute bargain for Los Blancos.
The Spaniard was extremely reliable and pulled off several memorable saves, including in the win over Manchester United in the 2012-13 Champions League last 16. He was involved in a controversial saga which saw Jose Mourinho prefer him over club legend Iker Casillas.
A lot of that seemed to stem from tension between the player and manager but Lopez was a worthy stand in. He won the Champions League in Los Merengues colours in 2014, one of two trophies claimed during his second spell at the Bernabeu.
3 - Gonzalo Higuain - (€12 million)
Gonzalo Higuain's European career started with Madrid when he arrived at the La Liga giants from Argentine outfit River Plate in January 2007. He was a real handful in Spain, posting 121 goals in 264 appearances which helped the club win the La Liga title in 2007, 2008 and 2012.
The Argentine frontman's best season was undoubtedly 2009-10 when he managed 27 league goals. He relished leading the line for Los Blancos and there have been many better hat-tricks than the one he bagged in a 6-3 win against Valencia in the 2010-11 campaign.
Higuain was more than just goals though as he held the ball up well before bringing others into play. He was an ideal center-forward for pacey wingers to work with but the arrivals of Karim Benzema and Kaka eventually led to his departure to Napoli in the summer of 2013 for €39 million.
2 - Casemiro - (Loan before €6 million)
Casemiro is the perfect example of Madrid's renowned scouting of Brazilian talent that has birthed superstars at the Bernabeu. He was relatively unknown when arriving on loan from Sao Paulo in January 2013.
Fast forward nine years and he had cemented his legacy as one of, if not, the greatest defensive midfield talent in the club's history. He formed a formidable midfield trio with Toni Kroos and Luka Modric which helped Los Merengues dominate Europe.
Casemiro did his side's dirty work so that Kroos and Modric could put their playmaking brilliance into practice. He won every major trophy on offer including five Champions Leagues by the time he headed to Manchester United for €70 million in the summer of 2022.
1 - Marcelo - (€6.5 million)
Marcelo will go down as one of the greatest left-backs in football history, certainly one of the best to pace up and down the channel as a Madrid player. There wasn't a dry eye in the house at his farewell ceremony and that speaks volumes of his impact at the Bernabeu.
The Brazilian joined the club from Fluminense in January 2007 for a ridiculously low fee. He quickly became a fan favorite, putting in inspired performances and proving just as effective going forward as he was defensively.
Madrid found their Roberto Carlos heir in his fellow countryman who appeared 546 times for the Spanish heavyweights. His longevity was remarkable as was his knack for grabbing an assist, doing so 104 times.
READ MORE REAL MADRID NEWS HERE: