He developed at Real Sociedad, helping them to qualify for the Champions League in 2013. He then transferred to Real Madrid for €32.2 million, the most they had ever paid for a Spanish player, returning to his first club for half of that fee two years later.
A product of local Real Sociedad's youth system, Illarramendi was born in Mutriku, Gipuzkoa, and he spent the vast majority of his first four senior seasons with the B team,[2] contributing 27 games and two goals in 2009–10 as the Basques returned to Segunda División B after one year out. On 19 June 2010, in the last day of the Segunda División campaign, as the first team had already sealed promotion to La Liga as champions, he made his first official appearance, in a 4–1 away loss against Elche CF.[3][4]
On 23 January 2011, Illarramendi made his top-division debut, in a 2–1 defeat at Villarreal CF.[5] The following month, he first appeared as a starter and played the full 90 minutes in another away loss (4–1 to RCD Espanyol);[6] the bulk of the season was spent, however, with the reserves in the third tier.
Illarramendi started in all of his 32 league appearances in 2012–13, as Real Sociedad finished fourth and qualified for the UEFA Champions League for the first time in ten years.[7] At the LFP Awards, he was named Breakthrough Player and Best Midfielder.[8]
Real Madrid
On 12 July 2013, Illarramendi signed a six-year contract with Real Madrid for a fee of €32.2 million,[9] the highest amount paid by the club for a Spanish player.[10] He made his official debut on 14 September by starting in a 2–2 away draw against Villarreal,[11] and scored his first goal on 18 December in a 2–0 home win over CD Olímpic de Xàtiva in the round of 32 of the Copa del Rey (also the aggregate score).[12]
Illarramendi scored his first league goal for the Merengues on 22 February 2014, after his long-range effort against Elche was deflected and the hosts won 3–0.[13] His second came on 5 April, when he opened an eventual 4–0 victory at his former team Real Sociedad in the 44th minute.[14] He was a regular in the domestic cup campaign, coming on as a late substitute for Ángel Di María in the 2–1 final defeat of FC Barcelona,[15] adding 11 matches – five starts – in the team's Champions League run but remaining on the bench as they clinched the trophy against Atlético Madrid in the final at the Estádio da Luz.[16][17]
On 26 August 2015, Illarramendi returned to Real Sociedad, signing a six-year deal[20][21]– the transfer fee was not officially disclosed by the clubs, but was stated in the media as being between €15–17 million, around half of the figure paid in the opposite direction two years previously.[22] He made his league debut in his second spell three days later, starting and being booked in a 0–0 home draw against Sporting de Gijón.[23] He recorded his first goal for the team in his second spell on 25 October, in a 4–0 win at Levante UD.[24]
In the 2016–17 campaign, Illarramendi had the second-highest number of interceptions across Europe's five major leagues behind only Chelsea's N'Golo Kante.[25] However, he was also noted for his poor disciplinary record, having racked up ten yellow cards by March 2017 including one in each of his four previous games.[26]
Illarramendi scored a career-best seven goals in 2017–18,[27] including braces in home and away victories over Deportivo de La Coruña. He had already exceeded his professional output for his whole career by February with his fifth goal.[28]
On 30 August 2019, Illarramendi suffered a broken fibula in a Basque derby match against Athletic Bilbao;[29] it was presumed the injury would keep him out for a few months, but it was found he required surgery to his shin and ankle ligaments, and he did not feature again prior to the season being halted in March 2020 due to the COVID-19 pandemic in Spain. The delay seemed to have given him time to return before its conclusion, but in June 2020 he suffered a further muscle injury on the training ground, and made no further appearances.[30]
Illarramendi played 16 times for the under-21s in two years. He represented them at the 2013 UEFA European Championship in Israel, being first choice as the nation won the competition and being selected in the team of the tournament.[35]
Illarramendi made his debut for Spain on 7 June 2017, playing the full 90 minutes in a 2–2 friendly draw with Colombia in Murcia.[38][39] He scored his first goal on 9 October that year, netting the game's only in Israel for the World Cup qualifying campaign.[40]
^Isasa, Xabier (26 August 2020). "Cinco años de más a menos" [Five years going from more to less]. Mundo Deportivo (in Spanish). Retrieved 15 September 2020.
^Badallo, Óscar (5 February 2018). "El Illarramendi con más gol" [The most-scoring Illarramendi]. Marca (in Spanish). Retrieved 9 May 2020.