Mathias Dahl Sauer (born 2 April 2004) is a Danish professional footballer who plays as an attacking midfielder for Ekstraklasa club Górnik Zabrze.
Sauer started playing football at Thorsager Rønde IF (TRIF). He later moved to AGF and then played for Silkeborg IF, before returning to AGF again in July 2019. After returning, 16-year old Sauer became an established played for the U19 team, although his young age.
Sauer did well with the U19s, which earned him his professional debut on 24 May 2021 - just over a month after his 17th birthday - in the Danish Superliga against FC Midtjylland, where he came on from the bench, playing the last 11 minutes of the game. On 6 March 2023, Sauer signed a new deal until June 2026 with AGF, meaning that he would be promoted to the first team squad from the start of the 2023âÂÂ24 season.
On 3 April 2024, AGF confirmed that they had extended Sauer's contract until June 2027 and that he was simultaneously loaned to Norwegian Eliteserien club FK Haugesund for the rest of the year. Despite a lot of chances, Sauer never made it in Norway and returned to AGF in 2025. It later emerged that Haugesund had wanted Sauer to stay at the club, but that AGF manager, Uwe Rösler, had asked for Sauer to return to the club.
On transfer deadline day in Norway, 27 March 2025, Sauer joined Norwegian First Division club Egersunds IK on a loan deal until June 2025, with an option to buy included. On 19 June 2025, AGF confirmed that the Norwegian club had exercised their option to buy and signed Sauer on a permanent deal lasting three years.
On 20 January 2026, Sauer joined Ekstraklasa club Górnik Zabrze on a deal until the end of June 2029, with an option for a one-year extension.