The Italian international had reportedly been locked in talks with the Spanish outfit over the past week and the deal has now been completed, according to Micciche.
"He's now a Sevilla player and one of Italy's best players in his position. He ultimately joined Sevilla as they're the club he wanted the most. Italian teams never took the final step to sign him, while Sevilla showed great interest in this fantastic player," Micciche told TMW Radio.
Vazquez, who has previously played in La Liga for Rayo Vallecano, scored eight goals and registered seven assists in Serie A last season to help Palermo avoid relegation.