In 1921 Sentís volunteered to serve in Morocco, where he was assigned to Regimiento de Luchana. In his later recollections he claimed to have served 2,5 years in Africa, but as late as in 1926 he was still reported in the press as serving in the Dark Continent. He completed the colonial experience as lieutenant before returning to his Almansa regiment. Sentís spent the late 1920s on routine garrison service; in 1927 he grew to captain and assumed command of a machine-gun sub-unit. When the Republic was declared Sentís remained capitán; the new military administration did not have much trust in his loyalty, especially that he did not make a secret of his Carlist, ultra-Right outlook. By the end of 1931 he was left with no clear assignment, reduced to the status of "disponibile". It is not clear whether he was reinstated before the assumed power, yet prior to 1934 he was already assigned to the 4th Somatenes Division. During the October 1934 revolutionary unrest in Catalonia Sentís commanded troops which seized the building of Tarragona Gobierno Civil, occupied by members of and Estat Catalá, and was vital to thwarting revolutionary attempts in the province. According to one source he assumed "funciones de gobernador Civil y de Orden Público", according to another he was formally nominated the provincial Delegado de Orden Público. In late 1935 he was back with his old Regimiento de Almansa.