Porto have confirmed the signing of forward Adrian Lopez from Spanish champions Atletico Madrid.
The 26-year-old Spain international joined Los Rojiblancos as a free agent in 2011, scoring 11 goals in 90 Primera Division matches.
Lopez only signed a new deal last December to tie him to the club until 2018, but the forward appears to have been tempted into joining the Portuguese side for the chance to work with former Spain U21 coach Julen Lopetegui.
Porto -- who have yet to confirm either the details of the transfer or the contract -- are keen to strengthen following a disappointing 2013-14 campaign in which they finished third in the Primeira Liga.
The forward is currently travelling with his new squad, and will take part in their preseason preparations.
Atletico later confirmed the transfer with a statement which read: "Atletico Madrid and Porto have reached an agreement for the transfer of Adrian Lopez to the Portuguese club.
"The Asturian striker leaves for the team that is coached by Spaniard Julen Lopetegui and with whom he has passed his medical.
"From the club we wish Adrian the best of luck in this new stage of his footballing career.''
Lopez scored during Atleti's Champions League semifinal victory over Chelsea, though they eventually went on to lose the final against city rivals Real.
Diego Simeone's side lost Diego Costa to Chelsea earlier this summer, but have replaced him with Bayern Munich forward Mario Mandzukic.