River Plate in 2019 Born in
González Catán,
Buenos Aires Province, Montiel was a product of the
Club Atlético River Plate academy. In October 2015, manager
Marcelo Gallardo called the 18-year-old up for the first time for an
Argentine Primera División game at
Defensa y Justicia; he was unused in the 1–0 loss on 15 October. He made his debut on 30 April 2016 in his one appearance of
that season, as a half-time substitute for
Pablo Carreras in a goalless draw at home to
Club Atlético Vélez Sarsfield; Gallardo had made 11 changes to his team with an eye to a
Copa Libertadores second leg against
C.S.D. Independiente del Valle. Montiel played four league matches the 2016–17 season. On 30 October, he was sent off in a 2–2 draw at
Arsenal de Sarandí. He lifted the
Copa Argentina trophy after playing all the matches from the last 16 to the
final, in which his team beat
Atlético Tucumán. He played in the
2017 Copa Libertadores, scoring a goal and assisting three, playing every minute from the quarter-finals to the semi-finals, where River Plate were defeated by
Club Atlético Lanús; his first career goal came on 1 November in a 4–2 loss at Lanús. In the 2017–18 season, Montiel played 35 matches, fifteen of them coming in the league. He made 14 appearances he made as the team lifted the Copa Libertadores at the
Santiago Bernabéu Stadium against
Superclásico rivals
Boca Juniors. Playing five matches in the Copa Argentina, the team were eliminated on penalties in the semi-finals against
Club de Gimnasia y Esgrima La Plata. The team secured a double that season as they beat Boca in the
Supercopa Argentina. The following season, Montiel played 12 matches in the league without being substituted. For the second season in a row, Montiel reached the Copa Libertadores final after twelve matches; however, River Plate would be defeated by
CR Flamengo. He won the Copa Argentina once more as River beat Central Córdoba - he played every minute in the cup run. After winning last season's Copa Libertadores, River contested the
FIFA Club World Cup where they finished third. An injury prevented him from playing in the Super Cup. After recovering, he returned to contest the Recopa as River overcame a 1–0 first-leg defeat to win the trophy with a 3–0 win against Club Athletico Paranaense.
Sevilla On 13 August 2021,
La Liga club
Sevilla FC signed Montiel on a five-year deal for €11 million. Manager
Julen Lopetegui signed him to compete with club icon
Jesús Navas at right back after the exit of
Aleix Vidal. He made his debut on 14 September in a
UEFA Champions League group stage 1–1 home draw against
FC Red Bull Salzburg, replacing Navas for the last three minutes. Eight days later, he made his league bow by starting against
Valencia CF at the
Ramón Sánchez Pizjuán Stadium, scoring in the 15th minute of a 3–1 win before making way for Navas before the hour. Montiel was
sent off on 6 November 2022 in a 1–1
Seville derby draw at
Real Betis for a 38th-minute foul on
Álex Moreno. On 31 May 2023, he scored the winning penalty in the
Europa League final against
Roma in a 4–1 victory in the penalty shootouts after a 1–1 draw, which secured their seventh title in the competition.
Return to Sevilla After one season in the Premier League, Montiel returned to Sevilla after completing his loan spell for Nottingham Forest after playing 802 minutes for the English team. Forest had shown interest in signing him permanently, as well as fellow English side
Everton FC and the Dutch team
Feyenoord, but ultimately Montiel returned to Spain.
Return to River Plate During the European winter club transfer period, Montiel was sold from Seville in January 2025 to his former club River Plate for a fee of $4.5 million, with a potential extra $500,000 for performance based results. His contract is until December 2028. He returned to his first club where he made 140 appearances with 6 goals from his debut in 2016. ==International career==