The 36-year-old Verdasco lost 6-3, 6-3 to his countryman.
Top seed and Australian Open finalist Dominic Thiem of Austria will play his first match on Tuesday against Brazilian Felipe Meligeni Alves.
Third-seeded Christian Garin of Chile advanced with a 4-6, 7-5, 7-6 (5) victory over Andrej Martin of Slovakia. Garin will face Argentine Federico Delbonis on Wednesday for a place in the quarterfinals of the clay-court tournament.
Delbonis won 6-2, 6-4 against Spaniard Roberto Carballes Baena.