Early career Mier began his career at
Rentistas in 2007 and transferred to
Fénix in 2008. He left the club in December 2010 after the
2010 Apertura season.
Peñarol Mier joined
Peñarol in January 2011. On 3 June 2011 he scored a crucial away goal in a
Copa Libertadores semi final clash against
Vélez Sársfield of
Argentina. Although
Peñarol were defeated on the night 2–1, they progressed to the finals on the away goals rule as the aggregate score was 2–2 over after they had won the 1st leg 1–0 in
Uruguay a week prior. Mier played both legs of the
finals, where they lost 2–1 on aggregate to
Santos.
Universidad Católica On 18 July 2011, it was reported that
Argentine Primera División club
Racing Club were interested in purchasing Mier for the next season, because
Mariano González recommended the player to Racing manager
Diego Simeone. Two days later, on 20 July,
Chilean Primera División club
Universidad Católica signed Mier on a three-year contract, which would keep him at the club until 2014. On 22 July, he was officially presented during a press conference. He made his
Primera División debut against
Deportes Iquique, and his first goal came on 13 August in a 4–0 win over
Unión La Calera. In November 2011, Mier won his first trophy as a professional when Universidad Católica won the
2011 Copa Chile, beating
Deportes Magallanes on penalties in the finals. In January 2014, he was loaned out to
Santiago Wanderers. In August 2015, he was loaned out to
Rentistas, rejoining the club after nine years. He impressed with Rentistas, scoring ten goals in 28 appearances. In January 2016, he was expected to join
Atlético Bucaramanga, but the deal fell through.
Muaither On 12 June 2016, Mier joined
Qatar Stars League club
Muaither and only made 2 appearances for the club before leaving.
Return to Peñarol In February 2017 he returned to Uruguay with Peñarol. On 28 April 2017, after Palmeiras beat Peñarol in the
2017 Copa Libertadores, there was a mass brawl, and Mier received a three match suspension for fighting Palmeiras defender
Felipe Melo. At the end of the Apertura tournament Mier left the club.
Junior In July 2017, Mier joined Colombian club
Atlético Junior to play the
2017 Copa Sudamericana,
2017 Copa Colombia, and
2017 Torneo Finalizacion. Mier played two matches in the knockout stages as Junior won the Copa Colombia, defeating
Independiente Medellín 3–1 on aggregate in the final.
La Equidad On 22 June 2018, Mier joined
Bogota-based club
La Equidad. He scored his first goal on 9 October 2018, in a 3–2 win against
Millonarios. On 3 April 2019, Mier scored his first goal of the
2019 Apertura in a 3–1 victory against
América de Cali. Four days later, he scored the opening goal in a 2–2 draw against his former club, Junior. Mier scored a goal in the
Copa Sudamericana quarter-finals against
Atletico Mineiro to put the match 1–1. However, Mineiro won the match 3–1 and eliminated La Equidad from the tournament on 28 August. On 14 September 2019, Mier scored the only goal in a victory against
Patriotas Boyacá. Mier scored three more goals in the 2019 Finalizacion tournament, against America de Cali, Patriotas again, and
Cúcuta Deportivo. Mier had a great individual season in the
2020 Categoría Primera A season, where he scored 10 goals in 19 appearances. His first two goals came in a 4–1 victory against Cucuta on 23 February. He scored another two goals, including an
Olympic goal, in a 4–0 victory against
Boyaca Chico in September. In October, he scored goals in victories against Independiente Medellin and Deportes Tolima, before adding his third brace of the season in a 2–1 victory against America at
Estadio Pascual Guerrero, which helped his team secure qualification for the playoffs in the last round.
Independiente Medellin Mier was announced as an
Independiente Medellín player on 18 December 2020. Mier was instrumental in Medellin's
2020 Copa Colombia title, scoring a goal and then his penalty in the shootout against
Deportes Tolima. Shortly after the conclusion of the
2021 Apertura, Mier was loaned out to
Central Córdoba, but only playing 354 minutes during 8 appearances.
Independiente Santa Fe In December 2021, Mier signed with
Independiente Santa Fe, scoring 5 goals and grabbing 6 assists in 41 appearances. He had an instant impact in his first season with the club, scoring 10 goals in 15 appearances. Despite his team suffering relegation at the end of the
2023-24 season, Mier continued to show his individual brilliance, scoring 13 goals in 31 appearances.
Bhayangkara In January 2023, Mier moved to the Asian continent, signing for Indonesian club
Bhayangkara halfway through the
2022–23 season. He had an instant impact in his first season, scoring 10 goals and providing 7 assists in just 15 appearances. Despite the team's relegation at the end of the
2023–24 season, Mier remained a key performer, recording 13 goals and 9 assists in 31 matches. He stayed with the club during the first half of their
Liga 2 campaign, contributing 2 goals in 13 appearances before returning to the top flight on loan.
Barito Putera (loan) On 7 January 2025, Mier joined
Barito Putera on loan for the remainder of the
2024–25 season. He became an immediate fan favorite, notably scoring a hat-trick in a 3–0 victory against
Persebaya Surabaya on 25 January. He finished his loan spell with 8 goals in 15 appearances.
Return to Uruguay and El Salvador Following the expiration of his contract with Bhayangkara, Mier returned to Uruguay and signed with
River Plate Montevideo on 1 August 2025. He made two substitute appearances for the club during the 2025 Clausura tournament. In January 2026, Mier moved to El Salvador to join
Zacatecoluca F.C. for the Clausura 2026 season. He made his debut for the club on 17 January 2026 in a league match against
C.D. Cacahuatique; he scored his first goal for the club in the 6th minute of the match, which ultimately ended in a 1–2 defeat. == Honours ==