Born in
Santiago de Compostela,
Galicia, Barreiro was a
Valencia CF youth graduate. He made his debut as a senior with
the reserves in the
2004–05 season, in the
Tercera División. After prolific lower league spells at
CD Lalín and
Algeciras CF, Barreiro joined
Cádiz CF on 31 January 2008. Initially assigned to the
B side, he made his first-team debut on 20 April 2008, coming on as a late
substitute for
Natalio in a 1–0
Segunda División away win against
CD Numancia. Barreiro scored his first professional goal on 18 May 2008, but in a 5–2 loss at
RC Celta de Vigo. After the club's
relegation to
Segunda División B, he was definitely promoted to the main squad. Released by Cádiz in the summer of 2009, Barreiro subsequently represented
Jerez Industrial CF,
Zamora CF,
CCD Cerceda,
Pontevedra CF and
Racing de Ferrol. With the latter, he scored a career-best 21 goals in two consecutive seasons, as his team achieved
promotion to the third division and
missed out another in the play-offs. On 27 June 2014, Barreiro returned to division two after six years, signing for
Deportivo Alavés. He scored 11 goals for the
Basques in his
debut campaign, including braces against
CA Osasuna and
CD Lugo, and added a further five in
the following as they returned to
La Liga after ten years. After making no league appearances during the first half of
the season, Barreiro terminated his contract on 22 December 2016 and joined second-tier club
Gimnàstic de Tarragona just hours later. He was
sent off for two
bookable offences on his debut – a 1–1 home draw with
CD Tenerife – the latter for not wearing the obligatory
shinpads. Barreiro signed a three-and-a-half-year deal with second-division Lugo on 28 January 2019. In
2020–21, he totalled a squad-best 12 goals for the 18th-placed side, the last outside the relegation zone. ==Honours==