He made his senior debut on 8 December 2009, coming on as a second-half substitute in a 0–2 Segunda División B away loss against UE Lleida.
On 19 June of that year he moved to RCD Mallorca, returning to youth football;[2] he was promoted to the reserves ahead of the 2011–12 season.
[9] His first goal came on 10 October, in a 1–1 home draw against CF Reus Deportiu; he ended the campaign as a starter, netting eight times as his side achieved a first-ever promotion to La Liga.
Gallar made his debut in the main category of Spanish football on 19 August 2018, starting and scoring a brace in a 2–1 away defeat of SD Eibar.
Gallar rescinded with Girona on 14 July 2022,[13] and signed a two-year deal with second division side Málaga CF the following day.