Mateus Fernandes brought his midfield skills to Southampton from Portugal, aged just 20, and was immediately thrown in at the deep end as Saints embarked on trying to survive their first season back in the Premier League. They were to fail abysmally, but amid the horrors of being in a team that came very close to creating a new low in terms of points won in a single season, he was one of the few successes.

His spirited and energetic performances endeared him to the fans and it came as a surprise to no one when he was named Player-of-the Season. There were hopes he could be persuaded to stay as the club faced second-tier football in the Championship. He featured in the first four games of the 2025-26 season, but despite only being one year into a five-year contract, the owners could not afford to turn down an offer in excess of £40m from West Ham which meant he was able to remain in the Premier League and work to getting a full Portuguese cap. His first international cap arrived in March 2026 but he was unable to prevent West Ham joining Saints in the second tier and for the second successive summer he left a relegated club to join a team still in the Premier League.