Sergio Almaguer Treviño (born 16 May 1969) is a Mexican former professional footballer who played as a centre-back, who is the current assistant manager of Liga MX club Monterrey.

[1] Almaguer made his professional debut with the former Mexico club Ángeles de Puebla on May 16, 1987.

[2][3] Almaguer started his career with former club Ángeles de Puebla, where he played 27 games and scored three goals.

[2] After the 1989–90 season Almaguer transferred to Querétaro, he appeared in 35 games and scored 11 goals.

[15] In January 2015, Almaguer won the 2015 CONCACAF U-20 Championship in Jamaica with the Mexico U-20 team also qualifying them for the 2015 FIFA U-20 World Cup in New Zealand.