He was also loaned to Levante and Getafe in La Liga, VfL Wolfsburg in the Bundesliga, and Roma in Serie A. Mayoral represented Spain up to under-21 level, earning 48 caps and scoring 29 goals.

[5] On 18 January 2015, Mayoral made his senior debut for the reserves, coming on as a 74th-minute substitute for Álvaro Jiménez in a 1–0 Segunda División B win over Getafe CF B.

[6] As a half-time replacement for Cristian Benavente on 25 April, he scored his first goal for the team in a 2–2 draw with Sestao River Club at the Estadio Alfredo Di Stéfano.

[11] He was sent off on 27 June at the end of the 2–1 loss to Rayo Vallecano in the final of the 2015 Copa del Rey Juvenil at the Estadio Alfonso Murube in Ceuta, for attacking an opponent.

[15] On 2 March 2016, due to injury to Karim Benzema, manager Zinedine Zidane gave Mayoral his first start for Real Madrid against Levante UD; he took a shot that went in as an own goal by goalkeeper Diego Mariño in a 3–1 win at the Estadi Ciutat de València.

[21] In August, Mayoral was named Most Valuable Player of the 2017 Major League Soccer All-Star Game for scoring Real Madrid's goal in their penalty shootout victory at Soldier Field, Chicago.

[29][30] He recorded his best La Liga figures of eight goals in 34 games in 2019–20, starting with a 3–2 loss at his parent club on 14 September and also including a 3–1 home win over leaders Barcelona on 2 November.

[34][35][36] He was joint top scorer with 7 goals in 13 appearances in the 2020–21 UEFA Europa League, including braces against Cluj in the group stage and Shakhtar Donetsk in the last 16.

[45] Mayoral scored in each of Spain's three qualification matches for the 2015 European Under-19 Championship: two in a 5–0 rout of Turkey and other goals in victories over rivals Portugal and hosts Georgia.

[49] On 7 October 2015, Mayoral made his debut for the under-21 team in a qualification match away to Georgia for the 2017 European Championship; he replaced Samu Castillejo with an hour played, and nine minutes later converted Saúl Ñíguez's assist in a 5–2 comeback victory.