been accelerated by both the left knee tendinopathy and a previous micro surgical repair in his right knee which had not been initially disclosed by Inter. They argued the combination of factors voided the contract, and Sunderland were therefore not obliged to buy the player. In 2017, the Court of Arbitration for Sport ruled that Sunderland were liable to pay Inter the transfer fee, rejecting Sunderland's argument on the basis that Sunderland's medical team had already found evidence of the micro-surgery to the right knee during the player's medical, but chose not to follow this up with Inter at the time. An appeal of the same ruling of FIFA was rejected. Nevertheless, as the transfer to Sunderland was considered complete and Álvarez did not sign a new contract with Sunderland, he was de facto a free agent after the expiry of loan meaning Sunderland were not able to recoup a transfer fee for the player when he later signed for Sampdoria. In August 2019, after a lengthy legal battle, a FIFA tribunal ruled that Sunderland were liable to pay Velez Sarsfield €362,500 as part of the FIFA solidarity mechanism. On the back of the announcement, Sunderland's chairman also revealed that Álvarez had appealed to the Court of Arbitration for Sport over the amount awarded for lost earnings during the first half of the 2015–16 season while his contract ownership was under dispute. Alvarez won the appeal in January 2021 and was awarded £4,770,000 in compensation from Sunderland. It took Sunderland's total costs in relation to the Alvarez deal to more than £20m. Sunderland attempted to sue the club doctor who performed the Alvarez's medical for £13m in an effort to recoup some of the losses, though the lawsuit (and a subsequent counter-suit by the doctor) was dropped in March 2021 when Sunderland was bought by new owner Kyril Louis-Dreyfus. Sampdoria In the last days of December 2015, he was linked with a move to Italian side Sampdoria which was finally concluded on 4 January of the following year, with Álvarez signing a contract until 30 June 2016. He was also given number 25 shirt for the second part of 2015–16 season. On 24 June 2016, Álvarez signed a new three-year contract. On 11 July 2018, he has officially terminated his contract with Sampdoria by mutual consent. International career On 18 August 2011, Álvarez was called up to Argentina's senior squad.