Mats Wieffer is a Dutch midfielder born in Borne in 1999. He began at FC Twente, developed with Excelsior, and then joined Feyenoord, where he became a key midfielder under Arne Slot. Wieffer helped Feyenoord win the Eredivisie in 2022-23 and gained European experience before moving to Brighton & Hove Albion in 2024. He made his Netherlands senior debut in 2023 after earlier domestic development rather than a long youth-international pathway.