The move brings an abrupt end to a spell that began with genuine promise: Gimenez scored in each of his first three appearances for Milan following his January 2025 arrival, a feat previously managed by only one other player in the club's history, Andriy Shevchenko.
Form and fitness deserted him after that bright start, and he found himself repeatedly overlooked by head coach Ruben Amorim, eventually left out of Milan's squad lists for both Serie A and European competition altogether.
Negotiations over the terms of his exit were far from straightforward. Porto's initial proposal was a free loan with a €15m option to buy, well below the figure Milan wanted given they had paid Feyenoord more than €30m for the striker only eighteen months earlier.
AC Milan instead pushed for a paid loan with an obligation to buy worth €20m, and the two clubs eventually settled in the middle: a loan without a fee, plus a €18m option that converts automatically into an obligation if Gimenez reaches certain appearance and playing-time thresholds during the season, with a further €2m available in bonuses. Agent Jorge Mendes is reported to have helped broker the compromise after talks stalled.
Gimenez travelled to Portugal on Sunday evening to undergo his medical and complete the paperwork, with the move officially confirmed by both clubs on Monday. Speaking briefly to reporters at Linate airport before his departure, the Mexico international struck an upbeat tone about the fresh start.
"Greetings and thanks to everyone. I'm happy to have this new opportunity, I feel excited and ready," he said.
The 25-year-old will link up with head coach Francesco Farioli's squad, which had been searching for centre-forward reinforcements while regular starter Samu Aghehowa recovers from injury. Porto compete in this season's Champions League league phase, offering Gimenez a stage to rebuild his reputation after a difficult period marred by fitness problems in Milan.
Announcing the departure, Milan thanked Gimenez for his professionalism and commitment during his time at the club, wishing him well for the new chapter of his career.
His exit is the latest in a series of departures from Milan's forward line this summer, following those of Rafael Leão and Christopher Nkunku, and comes as the club continues working to move on other fringe players, including Youssouf Fofana and Fikayo Tomori.