On 4 April 1981, he benefitted from injury to starter Mariano García Remón to make his La Liga debut, playing 71 minutes in the 3–1 away win over UD Salamanca.
[3][4] Agustín conquered the Ricardo Zamora Trophy for 1982–83 (29 matches, 25 goals),[5] but was almost always only a backup, consecutively to Miguel Ángel, José Manuel Ochotorena and Francisco Buyo.
[9][10] In his last four seasons, Agustín partnered Fernando Redondo at CD Tenerife – his teammate would later play at Real Madrid – helping the insular side to finish fifth in 1992–93 and qualify for the UEFA Cup for the first time ever.
In two consecutive years, his main club would lose the league to FC Barcelona in the last round after losses against Tenerife.
[4][11][12] Agustín retired in 1994 at the age of 34, and had a brief goalkeeping coach spell (along with other undefined roles) with his last team.