Marín joined Napoli from Madrid in the summer of 2024 for €12m before spending this season on loan at Villarreal. He made 30 competitive appearances across the campaign, including 22 in La Liga, contributing one goal and one assist. Villarreal hold a non-mandatory purchase option of €12m, but there is no obligation for the club to trigger it.
Madrid structured the original sale with two staggered buyback clauses that give them significant control over Marín's destiny. The first, worth €25m, can be activated this summer. If not exercised, a second clause at €35m becomes available in the summer of 2027. Madrid must also be consulted before any substantial conversations with other interested clubs can be concluded.
Diario AS reports that Madrid have been monitoring Marín closely throughout his loan spell. Incoming manager José Mourinho has identified defensive reinforcement as the most urgent priority for the squad rebuild, with David Alaba leaving when his contract expires and Éder Militão having suffered persistent injury problems this season.
Marín has not publicly pushed for a return but has never closed the door on it. At 24 and under contract with Napoli until 2029, he is entering the window as one of the more intriguing pieces on the La Liga transfer board — technically owned by one club, on loan at a second, and closely watched by a third that built him from the academy.
Whether Mourinho chooses to activate the €25m clause or wait for a cheaper alternative elsewhere will be among the first significant transfer decisions of his second tenure.