The Celta Vigo forward will arrive at Anfield as the Reds' second recruit of the summer, "subject to documentation being completed", following his Wednesday medical
The 25-year-old will officially become a Reds player "subject to documentation being completed".
Aspas is understood to have completed a medical on Wednesday, after which his agent and brother, Jonathan, confirmed that "only bureaucratic issues remain unresolved".
The departing Celestes star, who can play as a centre forward or on the flanks, is believed to have cost Liverpool £7 million after an impressive season in a struggling team.
Aspas scored 12 goals in La Liga as Celta narrowly avoided relegation from the Spanish top flight.
The striker becomes Brendan Rodgers's second acquisition of the summer, following the arrival of Kolo Toure on a free transfer from Manchester City.