In Mateos's sculpture, this 1968 piece entitled "El Guerrero" (The Warrior) is the transitional work between the figuration he had developed until now and the abstract work to come.

It shows the abandonment of organic form and a preference for geometric form. Ángel Mateos carries out an exercise in the schematisation of form, where the human figure is translated into emphatic geometric volumes with hard edges and all straight lines. In this way Mateos places himself in the sphere of cubist representation.

But it is not precisely pigeonholing himself that the sculptor longs for, although he does see in this work a path to follow. The rotundity of the volumes leads him to forget about the figure represented, and to perceive the whole as a pure volumetric construction. He sensed that he could dispense with the referent and make a sculpture of his own.

He then conceived the idea that art must have a transcendental intention, where the work of art has to be representative of its time.

This work opens the way to the mature work of Ángel Mateos, in which the material he will use, concrete formwork, will be decisive.