On 4 July 2011, he joined RCD Mallorca B in the third tier,[5] being promoted to the main squad shortly after[6] and making his La Liga debut on 29 October in a 0–5 loss at FC Barcelona.
[7] Álvaro's first two goals in the top flight earned the Balearic Islands side four points, as he scored against Athletic Bilbao (1–1, home)[8] and Sporting de Gijón (3–2, away)[9] – on both occasions, he was fielded by manager Joaquín Caparrós in the starting XI.
Having activated Álvaro's €1.5 million release clause, English Championship club Birmingham City signed him on 6 August 2019 on a three-year contract.
[17] He started the next match, at home to Barnsley three days later, and won the ball that led to Lukas Jutkiewicz's opening goal before controlling a lofted pass from Steve Seddon on his chest and lobbing the goalkeeper to complete a 2–0 win.
[19] With Jutkiewicz rested for the 27 November visit to Sheffield Wednesday, Álvaro opened the scoring in a 1–1 draw with a goal that head coach Pep Clotet hoped would restore "calm and confidence" to the player.
[21][22] On the final day of the January 2020 transfer window, Álvaro signed for Segunda División leaders Cádiz CF on loan until 30 June, with the intention of making the move permanent.
[28] Having begun the season in self-isolation because of contact with someone who had tested positive for COVID-19, Álvaro was not selected in the matchday squad when he did become available, amid speculation that he might leave on loan.
[29] Included on the bench for the visit of Granada the day before the transfer window closed, he came on at half-time, and within three minutes had attempted and failed with an overhead kick that ended up as an assist for Iván Alejo's equalising goal.
[35][36] His first goal came from the penalty spot to complete a 2–1 win at home to Cartagena on 7 March,[37] but it proved to be his only one from 14 appearances, mainly from the bench,[38] as Mallorca were promoted to La Liga.
[39] Álvaro joined another second-tier club, Real Zaragoza, on 15 August 2021 on loan for the season;[39] the deal included a costly obligation to purchase depending on appearances and promotion.