Aprofitant la lesió de [[José Ignacio Fernández Iglesias|Nacho]] i la sanció a Ramos,<ref>{{cite news|url= http://www.marca.com/en/football/real-madrid/2018/04/10/5acc95b8468aebb9178b461f.html|title=Vallejo back in full training ahead of Juventus call-up|newspaper=Marca|date=10 abril 2018|accessdate=12 abril 2018}}</ref> Vallejo va debutar a la [[Lliga de Campions de la UEFA]] l'11 d'abril de 2018, jugant el partit sencer en una derrota per 1–3 a casa contra la [[Juventus FC]] al partit de tornada dels [[UEFA Champions League 2017–18|quarts de final]], un resultat que va classificar el Madrid per a les semifinals, 4–3 en el còmput global.<ref>{{cite web|url= https://www.bbc.co.uk/sport/football/43632225|title=Real Madrid 1–3 Juventus|publisher= [[BBC Sport]] |date=11 abril 2018|accessdate=12 abril 2018}}</ref> Va ser la seva única aparició,<ref>{{cite web|url= https://www.rcnradio.com/deportes/asi-llegan-las-plantillas-de-real-madrid-y-liverpool-la-final-de-la-champions|title=Así llegan Real Madrid y Liverpool a la final de la Champions| publisher= [[RCN Radio]] |language= castellà |date=25 maig 2018|accessdate=29 maig 2018}}</ref> en una competició que el Madrid va acabar guanyant per tercer cop consecutiu i 13è en total.<ref>{{cite web|url= http://www.uefa.com/uefachampionsleague/season=2018/matches/round=2000885/match=2021711/postmatch/report/index.html|title=Madrid beat Liverpool to complete hat-trick|publisher=UEFA|date=26 maig 2018|accessdate=28 maig 2018}}</ref>
== Carrera internacional ==
On 7 març 2013, Vallejo appeared with the [[Spain national under-16 football team|Spain under-16 team]] in a [[Exhibition game|friendly]] with [[Hungary national under-17 football team|Hungary]].<ref>{{cite web|url= http://www.realzaragoza.com/noticias/34903|title=El zaragocista Jesús Vallejo titular en el España – Hungría Sub-16|trans-title=Zaragoza's Jesús Vallejo starts in Spain – Hungary Under-16|publisher=Real Zaragoza|language= castellà |date=7 març 2013|accessdate=27 agost 2014}}</ref> He earned his first [[Cap (sport)|cap]] for [[Spain national under-21 football team|the under-21s]] on 26 març 2015 at the age of 18, starting in the 2–0 win against [[Norway national under-21 football team|Norway]] in [[Cartagena, Spain|Cartagena]] in another exhibition game.<ref>{{cite web|url= http://www.eurosport.es/futbol/seleccion-espanola/2011/deulofeu-y-munir-encumbran-a-la-sub-21_sto4654942/story.shtml|title=España-Noruega: Partidazo de Deulofeu y gol Munir (2–0)|trans-title=Spain-Norway: Big game from Deulofeu and Munir goal (2–0)|publisher= [[Eurosport]] |language= castellà |date=26 març 2015|accessdate=31 juliol 2017}}</ref><ref>{{cite web|url= http://www.realzaragoza.com/noticias/jes-s-vallejo-sube-un-nuevo-pelda-o-en-su-carrera-con-su-debut-en-la-sub-21|title=Jesús Vallejo sube un nuevo peldaño en su carrera con su debut en la Sub-21|trans-title=Jesús Vallejo climbs another step with Under-21 debut|publisher=Real Zaragoza|language= castellà |date=27 març 2015|accessdate=31 juliol 2017}}</ref>
Selected for the [[2017 UEFA European Under-21 Championship|2017 Under-21 European Championship]] finals by manager [[Albert Celades]],<ref>{{cite web|url= http://www.football-espana.net/64173/spain-reveal-euro-u21-championship-squad|title=Spain reveal sub-21 Championship squad|publisher=Football España|date=19 maig 2017|accessdate=31 juliol 2017}}</ref> Vallejo played four times for the eventual runners-up.<ref>{{cite news|url= https://en.as.com/en/2017/06/20/football/1497949717_765343.html|title=Portugal 1–3 Spain: UEFA Under 21 Euro match report, Spain advance to semi-finals|newspaper= [[Diari AS]] |date=20 juny 2017|accessdate=31 juliol 2017}}</ref><ref>{{cite web|url= https://www.bbc.com/sport/football/40451698|title=Germany sub-21 1–0 Spain sub-21|publisher=BBC Sport|date=30 juny 2017|accessdate=31 juliol 2017}}</ref> Even though he was not part of the squad of 23 for the [[2018 FIFA World Cup]] finals, he was picked by [[Spain national football team|full side]] head coach [[Julen Lopetegui]] for a friendly with [[Switzerland national football team|Switzerland]] to be held on 3 June.<ref>{{cite news|url= http://www.elperiodicodearagon.com/noticias/deportes/espana-examina-amistoso-suiza_1288254.html|title=España se examina en un amistoso ante Suiza|trans-title=Test for Spain in friendly against Switzerland|newspaper= [[El Periódico de Aragón]] |language= castellà |date=3 juny 2018|accessdate=3 juny 2018}}</ref>
