[1] He played for Real Madrid and earned 4 caps for the Spain national football team, competing at the 1924 Summer Olympics.

[3] In that same season, and despite his early age of just 15, he debuted with the first team in a Central Regional Championship match against Racing de Madrid, and he quickly became one of the club's benchmarks at the time.

At the time of his retirement in 1929 (aged 26), he was the second top scorer of the Madrid team, only surpassed by the 68 goals from teammate Santiago Bernabéu.

[5] In 1943, years after his professional retirement, the white club organized a tribute match in his honour between the people of Madrid and Barcelona, ending with a one-goal tie.

[6] Being an Madrid FC player, he was eligible to play for the 'Centro' (Madrid area) representative team, and he was part of the squad that participated in two tournaments of the Prince of Asturias Cup, an inter-regional competition, in 1922–23 and 1923–24, and although the first campaign ended with a shocking quarter-final exit at the hands of Galicia, in which Monjardin scored Madrid's consolation goal in a 1–4 loss, the second campaign was much better, largely thanks to Monjardin as he scored twice in their 2–1 win over a Andalusia XI in the semi-finals, followed by what appeared to have been an extra-time winner against Catalonia in the final to seal Madrid's second Prince of Asturias Cup title, but a last-minute equaliser from Emili Sagi-Barba forced a replay in which he scored again, netting twice in the first-half, but his efforts were in vain as Catalonia took the title with a 3–2 win.