[1] On 4 September 2015, Mancilla was named manager of Tercera División side UD Lara [es].
[2] The following April, he joined Juan Domingo Tolisano's staff at Carabobo, as an assistant manager.
[3] Mancilla followed Tolisano to Mineros de Guayana,[4] Deportivo Táchira[5] and Chilean side Deportes Antofagasta,[6] always as his assistant.
On 28 March 2022, he was named manager of Primera División side Deportivo Lara, after Jorge Durán resigned.
[7] Mancilla's first match in charge of the Rojinegro occurred on 31 March 2022, a 0–2 loss against former side Táchira.