ParaguayMit Atlético Mineiro gewann er 2021 die brasilianische Meisterschaft und den Copa do Brasil. Zudem wurde er mit Cerro Porteño paraguayischer Meister.
Junior Alonso ist ein paraguayischer Innenverteidiger, der für seine Zeit bei Vereinen wie Lille OSC und Atlético Mineiro bekannt ist. Er begann seine Profikarriere in Paraguay bei Cerro Porteño und wechselte später nach Europa. Alonso hat auch für die paraguayische Nationalmannschaft gespielt.
Alonso ist ein robuster und zweikampfstarker Innenverteidiger, der sich durch seine Kopfballstärke und sein gutes Stellungsspiel auszeichnet. Er ist zudem ballsicher und kann das Spiel von hinten aufbauen. Seine Schnelligkeit ist jedoch nicht überragend, was gegen schnelle Angreifer ein Nachteil sein kann.
| Season | Comp | Apps | G | A | YC | RC | Min |
|---|---|---|---|---|---|---|---|
| 25/26 | International Friendlies | 7 | 0 | 0 | 1 | 0 | 491 |
| 23/24 | World Cup qualification South America | 12 | 1 | 1 | 4 | 0 | 1062 |
| 23/24 | Russian Cup | 6 | 0 | 0 | 0 | 0 | 356 |
| 23/24 | Premier Liga | 29 | 0 | 3 | 4 | 0 | 2610 |
| 23/24 | International Friendlies | 2 | 0 | 0 | 1 | 0 | 180 |
| 22/23 | Russian Cup | 7 | 0 | 0 | 3 | 0 | 630 |
| 22/23 | Premier Liga | 12 | 1 | 0 | 0 | 0 | 1080 |
| 22/23 | International Friendlies | 3 | 0 | 0 | 0 | 0 | 258 |
| 21/22 | Premier Liga | 0 | 0 | 0 | 0 | 0 | 0 |
| 21/22 | International Friendlies | 0 | 0 | 0 | 0 | 0 | 0 |
| 2026 | Copa Sudamericana | 4 | 0 | 0 | 1 | 0 | 335 |
| 2026 | Campeonato Mineiro | 5 | 0 | 0 | 0 | 1 | 450 |
| 2026 | Copa do Brasil | 0 | 0 | 0 | 0 | 0 | 0 |
| 2026 | Campeonato Brasileiro Série A | 10 | 0 | 0 | 2 | 0 | 900 |
| 2025 | Copa Sudamericana | 13 | 0 | 0 | 3 | 0 | 1148 |
| 2025 | Campeonato Mineiro | 9 | 0 | 0 | 2 | 0 | 765 |
| 2025 | Copa do Brasil | 8 | 0 | 0 | 2 | 0 | 720 |
| 2025 | Campeonato Brasileiro Série A | 31 | 1 | 1 | 5 | 2 | 2619 |
| 2024 | Copa América | 0 | 0 | 0 | 0 | 0 | 0 |
| 2024 | Copa Libertadores | 7 | 0 | 0 | 0 | 0 | 630 |
| 2024 | Copa do Brasil | 8 | 0 | 0 | 2 | 0 | 715 |
| 2024 | Campeonato Brasileiro Série A | 12 | 1 | 0 | 2 | 0 | 1048 |
| 2022 | Copa Libertadores | 10 | 0 | 1 | 0 | 0 | 840 |
| 2022 | Campeonato Mineiro | 1 | 0 | 0 | 0 | 0 | 6 |
| 2022 | Copa do Brasil | 2 | 0 | 0 | 0 | 0 | 168 |
| 2022 | Campeonato Brasileiro Série A | 31 | 0 | 2 | 4 | 0 | 2599 |
| 2021 | Copa América | 5 | 1 | 0 | 1 | 0 | 450 |
| 2021 | Copa Libertadores | 12 | 0 | 0 | 0 | 0 | 1080 |
| 2021 | Campeonato Mineiro | 9 | 0 | 1 | 2 | 0 | 765 |
| 2021 | Copa do Brasil | 8 | 0 | 0 | 1 | 0 | 720 |
| 2021 | Campeonato Brasileiro Série A | 22 | 1 | 0 | 5 | 0 | 1980 |
| 2020 | Copa Libertadores | 2 | 0 | 0 | 0 | 0 | 114 |
| 2020 | Campeonato Mineiro | 6 | 0 | 0 | 2 | 0 | 540 |
| 2020 | Campeonato Brasileiro Série A | 32 | 1 | 2 | 8 | 0 | 2878 |
| 2020 | Copa Superliga (-19/20) | 1 | 0 | 1 | 0 | 0 | 90 |
| 2019 | Supercopa Argentina | 0 | 0 | 0 | 0 | 0 | 0 |
| 2019 | Copa América | 4 | 0 | 0 | 1 | 0 | 360 |
| 2019 | Copa Libertadores | 2 | 0 | 0 | 0 | 0 | 180 |
| 2019 | Copa Superliga (-19/20) | 5 | 0 | 0 | 2 | 0 | 357 |
| 2019 | Copa Argentina | 2 | 0 | 0 | 2 | 0 | 180 |
| 2016 | Primera División Clausura | 0 | 0 | 0 | 0 | 0 | 0 |
| 2016 | Primera División Apertura | 0 | 0 | 0 | 0 | 0 | 0 |
| 2016 | Copa Sudamericana | 10 | 0 | 1 | 2 | 0 | 900 |
| 2016 | Copa Libertadores | 8 | 1 | 1 | 3 | 0 | 699 |
| 2016 | Copa América Centenario 2016 | 0 | 0 | 0 | 0 | 0 | 0 |
| 2015 | Primera División Paraguay Playoffs | 0 | 0 | 0 | 0 | 0 | 0 |
| 2015 | Primera División Clausura | 0 | 0 | 0 | 0 | 0 | 0 |
| 2015 | Primera División Apertura | 0 | 0 | 0 | 0 | 0 | 0 |
| 2015 | Copa América | 0 | 0 | 0 | 0 | 0 | 0 |
| 2015 | Copa Libertadores | 0 | 0 | 0 | 0 | 0 | 0 |
| 2014 | Copa Sudamericana | 4 | 0 | 0 | 1 | 0 | 298 |
| 2014 | Copa Libertadores | 8 | 0 | 0 | 2 | 0 | 712 |
| 2013 | Copa Sudamericana | 2 | 0 | 0 | 0 | 0 | 180 |
| 2013 | Copa Libertadores | 0 | 0 | 0 | 0 | 0 | 0 |
| 2013 | U-20 South American Championship | 2 | 1 | 0 | 0 | 0 | 119 |
| 2013 | U20 World Cup | 4 | 0 | 0 | 1 | 0 | 390 |
| 20/21 | World Cup qualification South America | 14 | 0 | 0 | 6 | 0 | 1166 |
| 19/20 | International Friendlies | 3 | 0 | 0 | 2 | 0 | 270 |
| 19/20 | Professional Football League (- 23/24) | 14 | 0 | 1 | 2 | 0 | 1149 |
| 18/19 | International Friendlies | 3 | 0 | 0 | 1 | 0 | 270 |
| 18/19 | Ligue 1 | 0 | 0 | 0 | 0 | 0 | 0 |
| 18/19 | LaLiga | 9 | 0 | 0 | 2 | 0 | 534 |
| 18/19 | Copa del Rey | 2 | 0 | 0 | 0 | 0 | 180 |
| 18/19 | Professional Football League (- 23/24) | 7 | 0 | 0 | 1 | 0 | 630 |
| 17/18 | International Friendlies | 2 | 0 | 0 | 1 | 0 | 180 |
| 17/18 | Coupe de la Ligue | 2 | 1 | 0 | 1 | 0 | 180 |
| 17/18 | Coupe de France | 2 | 0 | 0 | 0 | 0 | 180 |
| 17/18 | Ligue 1 | 34 | 2 | 0 | 3 | 0 | 2779 |
| 16/17 | International Friendlies | 2 | 0 | 0 | 0 | 0 | 180 |
| 16/17 | Coupe de France | 2 | 0 | 0 | 0 | 0 | 180 |
| 16/17 | Ligue 1 | 12 | 0 | 1 | 1 | 0 | 956 |
| 15/16 | World Cup qualification South America | 8 | 1 | 1 | 3 | 0 | 705 |
| 15/16 | International Friendlies | 0 | 0 | 0 | 0 | 0 | 0 |
| 14/15 | International Friendlies | 2 | 0 | 0 | 0 | 0 | 180 |
| 13/14 | International Friendlies | 3 | 0 | 1 | 0 | 0 | 250 |
| 12/13 | International Friendlies | 2 | 0 | 0 | 1 | 0 | 180 |
| 11/12 | World Cup qualification South America | 1 | 0 | 0 | 0 | 0 | 90 |