The Reds swooped for the 26-year-old last summer after being impressed with his form for La Liga minnows Celta Vigo.
Despite being a regular goalscorer in his homeland, Aspas managed just one effort on Merseyside – a swivelling finish against Oldham in the FA Cup.
Even with Luis Suarez set to leave, Brendan Rodgers is ready to deplete his forward line further by letting the striker head off, with Sevilla interested.
Liverpool are unlikely to get anymore than half of the £7.7m they paid just 12 months ago, but are willing to take the hit to clear space for new arrivals.
Aspas himself is keen to get back to Spain and play regularly after voicing his frustration at his situation last term.
Fabio Borini’s comeback and Rickie Lambert’s signing look likely to block any route he may have to being Daniel Sturridge’s deputy, and his position could be weakened further in the coming weeks with Liverpool set to spend big.