At 26, Mac Allister has made a home for himself in Belgium, becoming one of Union’s leaders. The son of former Argentina international Carlos and the older brother of Liverpool midfielder Alexis, he has built a quieter footballing life, one step removed from the spotlight that now follows his family name.
“When the draw came out, I was happy,” he said. “But we all know it will be difficult. For me, Inter are one of the top five teams in Europe.”
His Champions League adventure began with a jolt of joy. Union's first-ever match in the competition brought a 3-1 win over PSV, with Mac Allister among the scorers. “It was like a dream,” he recalled. “We won our first Champions League game and I scored, away from home. Our fans travelled in huge numbers, two, maybe three thousand, and they were louder than the home crowd. To start like that was incredible for us.”
That goal, he said, brought “a feeling of great happiness”. His wife was in the stands. “We’re expecting our first child in December,” he added, smiling. “That made it even more special.”
Reality arrived swiftly, though, as Union’s next game ended in a 4-0 defeat at home to Newcastle. “That can happen when you face teams of that level,” he said, shrugging. “Now we move on to Inter. Personally, I think they’re one of the best sides in Europe. Every year when we make predictions about who will reach the final, I always say Inter. Last season they did, and this year they’re still one of the favourites.”
Martinez will be a familiar opponent. The pair once shared Argentina’s U20 camp before a tournament in Ecuador. “We played against each other several times as kids,” Mac Allister said. “Lautaro was already one of the stars.”
He has studied Inter’s captain closely. “He’s unpredictable, he can drop deep, attack space, drift wide. He’s too intelligent for you to say, ‘This is how you mark him.’ You just prepare mentally, focus on details, and adapt. On the pitch, there are no friends, only respect. That respect means you never pull out of a challenge.”
Family and Argentina dream
Talk turns to his brother. “Alexis and Lautaro have a great relationship,” he said. “They’ve shared so much with the national team. Lautaro’s been a great revelation for Argentine football. What he’s done at Inter is extraordinary.”
Does he dream of joining them one day? “Of course. I’m realistic; Alexis is closer to that level, but I work every day for it. The national team has a great spirit, everyone pulling together. I’d love to join them, but the guys there deserve their place.”
One of Mac Allister’s fondest memories came in 2023, when Union faced Liverpool in the Europa League. “I usually never go out before kick-off, but that day I wanted to,” he said. “I waited for Alexis on the pitch, messaged him to hurry up. We shared a mate (drink) at Anfield… that gave me goosebumps. It was one of the best moments of my career. Playing with or against your brother is something you never forget.”
Italian lessons: Cannavaro and De Rossi
For a player shaped in Argentina but inspired by Italy, it’s no surprise his footballing references lean that way. “My first memory is the 2006 World Cup,” he said. “(Fabio) Cannavaro was incredible. To see a defender of that height win the Ballon d’Or stayed with me. I once joked with (Daniele) De Rossi at Boca Juniors: ‘Hey, don’t disrespect Cannavaro!’”
De Rossi’s brief spell at Boca left a mark. “It was surreal,” Mac Allister said. “You walk into the dressing room and there’s De Rossi, covered in tattoos, but he was humble, spoke Spanish, and treated everyone equally. On the pitch, he was so intelligent, always finding the right pass. He had a great connection with Alexis. It’s a shame injuries stopped him playing more, but for us it was unforgettable.”
If there’s one city he still hopes to visit through football, it’s Naples. “When the draw was made, we were all hoping for Napoli,” he said. “For Argentinians, going to Naples is special. I’ve never been, but everyone says it’s amazing. When we saw Inter and Atalanta instead, we were a bit disappointed. But who knows, maybe next year.”
On Tuesday, he will once again face Martinez, this time on Europe’s biggest stage. “Inter are among the best,” he said. “But that’s why we play football, to test ourselves against the best.”
For a defender who once dreamed of following Cannavaro, learned from De Rossi, and now stands on the Champions League stage alongside his brother’s generation, Kevin Mac Allister is proving there’s more than one way from Buenos Aires to the top.