Clausen is a product of BSF,[2] where he also started his senior career at in 2014, playing in the Denmark Series.[3][4] In the summer 2015, he moved to Greve Fodbold, who also played in the Denmark Series.[5] Ahead of the 2018–19 season, Clausen then joined Danish 2nd Division side Akademisk Boldklub, where he played for one year.[6]
After leaving AB, Clausen joined another 2nd Division club, Brønshøj Boldklub, on a one-year deal. In the summer 2020, he extended his contract with one further year, after playing 23 games in his first season.[7]
On 31 August 2021, Clausen joined Danish 1st Division side Hvidovre IF.[8] In his first season at the club, he made 10 league appearances and 3 in the cup. After a good start to the 2022–23 season, Clausen was rewarded in December 2022 with a new contract, signing until June 2024.[9] Clausen ended up playing 16 games and scoring one goal, contributing to Hvidovre's promotion to the 2023-24 Danish Superliga. Clausen, however, sat out with an injury for almost half of the 2022–23 season until November 2023. He was only back in the squad on 3 December 2023, in a match against Brøndby IF, where he made his comeback match and his debut in the top Danish league.[10]