After a strong start to the 2021–22 season with two assist and one goal in the first three games of the campaign for Randers, Greve was sold to 2020–21 Danish Superliga champions Brøndby on 4 August 2021, signing a deal until June 2025.MATHIAS GREVE NY MAND I GULT, brondby.com, 4 August 2021 He made his debut against rivals Copenhagen on 8 August in a 2–4 away loss.
