Although born in Medina del Campo, Lázaro grew up in Olmedo (also located in Valladolid), where he began to play football.
Aged 12, he joined Real Valladolid's youth system[1] and played his first seasons with the reserves, suffering relegation to the fourth division in his first year.
First-team coach José Luis Mendilibar gave Lázaro his first chance to appear in La Liga, in one of his last games before being sacked: on 17 January 2010, he played the full 90 minutes against Racing de Santander in a final 1–1 away draw.
[2] After appearing in six of the following seven matches – three starts, but five defeats – under new manager Onésimo Sánchez, he suffered a serious injury[3] and could not help prevent the Castile and León side's relegation, after a 0–4 loss at FC Barcelona.
For 2010–11, Lázaro was definitely promoted to Valladolid's first team, but made no official appearances whatsoever during the season, due to a bout of hyperventilation[4] and an ankle injury.