Valero made an immediate impact at the "Viola", scoring five league goals in 37 games in his first season and providing 11 assists as the team qualified to the Europa League. He scored his first goal in 2013–14 on 15 September in a 1–1 home draw against Cagliari, and, on 2 November, contributed to a 2–0 success at Milan; subsequently, he was named in Goal.com's "Serie A Team of the Season".