Sánchez's debut season for Barcelona was mired with short-term injuries. He made his debut on 14 August 2011 against archrivals Real Madrid in the 2011 Supercopa de España first leg away match, suffering a thigh injury after a challenge by Marcelo.  Barcelona won the tie 5–4 on aggregate. He made his return two weeks later as a substitute in the 2011 UEFA Super Cup, won by Barca 2–0. Alexis then started the opening match of La Liga, at home against Villarreal, and scored his first goal in a 5–0 win. A week later, on 10 September, he was stretchered off after 30 minutes following a challenge from Dani Estrada in a domestic league match against Real Sociedad. Sánchez returned on 1 November in an away match against Viktoria Plzeň.  On 10 December, he scored Barça's equaliser against Real Madrid in a match they went on to win 1–3 away at the Santiago Bernabéu Stadium. On 14 February 2012, Sánchez scored the first and second UEFA Champions League goals of his career in Barcelona's 3–1 victory against Bayer Leverkusen.