To mark the opening of the winter transfer window in Spain, UEFA.com selects ten of the most eye-catching January signings to have been made in the Liga.
Fernando Torres: AC Milan to Atlético Madrid, 2015 (loan)
"One day you'll have to explain to me what I did to be treated like this," said a stunned Torres as he walked around the pitch at the Vicente Calderón, his name chanted by 45,000 fans who had braved the January cold to see his long-awaited return. He could hardly have got off to a better start in his second spell with the club, scoring twice against Real Madrid to knock them out of the Copa del Rey at the last-16 stage.
Diego López: Sevilla to Real Madrid, 2013 (€3.5m)
With Iker Casillas nursing a broken wrist, López joined the Whites for a second time and fans quickly warmed to him after a great display on his latest debut against Barcelona. The bond grew stronger after he helped Madrid through a testing UEFA Champions League tie versus Manchester United with a string of fine saves, prompting José Mourinho to hail him as the Merengues's best performer at Old Trafford.
Juanfran, Osasuna to Atlético Madrid, 2011 (€4m)
Something of a late bloomer, Juanfran did not really progress at Osasuna until his early 20s, following spells at Real Madrid and Espanyol. He was one of the Navarran club's top attackers when Atlético signed him at the start of 2011, but it was coach Gregorio Manzano who had the foresight to move him to right-back. Now first choice for club and country, Juanfran is still reaping the benefits.
Nikola Žigić: Valencia to Racing Santander, 2009 (loan)
The Serbia forward established himself in Europe in his first spell at Racing, leading to a €15m move to Valencia, but his second stint in Cantabria proved more significant. Short of playing time under Unai Emery, Žigić returned to a struggling Racing side in an attempt to spare them from relegation. He delivered, scoring 13 goals in 19 appearances to help steer the club to safety.
Ivan Rakitić: Schalke to Sevilla, 2011 (€1.5m)
Sevilla's renowned sporting director Monchi has built a reputation for unearthing talented footballers ahead of his rivals and the capture of Rakitić was one of his greatest coups. The Croatia midfielder quickly grew into one of the club's leaders, becoming the first non-Spaniard to wear the captain's armband since Diego Maradona and inspiring them back to the glory years of the Juande Ramos era. He was named man of the match in the 2014 UEFA Europa League final defeat of Benfica before joining Barça for €18m.
Gonzalo Higuaín: River Plate to Real Madrid, 2007 (€12m)
Trailing Barcelona at Christmas and desperate to reclaim the title, Madrid turned to 19-year-old Higuaín, who had taken on huge responsibility with River. A winner against Espanyol and an equaliser at Atlético helped deliver the Liga crown six months later, but the Argentina striker played a far greater role in the title wins of 2007/08 and 2011/12, netting 22 times in the latter campaign. His value rocketed and in 2013 he was sold to Napoli for €40m.
Diego Costa: Atlético Madrid to Rayo Vallecano, 2012 (loan)
With the forward recently recovered from a knee injury and in need of games, and with Rayo floundering around the relegation zone, Costa's six-month loan suited all parties. He forged a profitable partnership with Michu and managed ten goals in 16 outings – enough to ensure Rayo survived. "He saved our lives," remembers his captain, David Cobeno. "There was a huge party in the dressing room afterwards and he was the player that shouted, jumped around and sang the most."
Tiago: Juventus to Atlético Madrid, 2010 (loan, free transfer)
The Portuguese initially joined the Rojiblancos on a six-month loan, starved of opportunities at Juventus. A successful stay resulted in an extended loan lasting a year, and then Atlético sought a permanent deal for a midfielder who was slowly but surely becoming one of their most important players. His influence grew under Diego Simeone, who embodies the same leadership traits as Tiago according to Atlético sporting director José Luis Caminero.
Martín Demichelis: Bayern München to Málaga, 2011 (undisclosed fee)
The Argentina defender was struggling for game time at Bayern and the ambitious Andalusian team, at the time led by Demichelis's former coach at River, Manuel Pellegrini, offered him the ideal escape. Demichelis immediately gave Málaga defensive stability, which resulted in them achieving a club-best fourth-place finish in his first full season. A sensational and thrilling run to the quarter-finals of the UEFA Champions League followed and there were no shortage of suitors for the resurgent centre-back, who eventually opted for Manchester City.
Marcelo: Fluminense to Real Madrid, 2007 (€7m)
Madrid took quite a gamble on bringing Marcelo, aged just 18 and with only one professional season under his belt, to the Santiago Bernabéu in 2007. However, nine years later, with the Brazilian international still racing up and down Madrid's left flank every week, this signing has proved to be one of the most shrewd in the capital club's modern history. "He has a lot more quality than I did," said Roberto Carlos, Madrid's explosive left-back for over a decade before Marcelo. "I was very quick, but Marcelo is too and he has a lot more ability with the ball."
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