Mumin was born in Accra and was a part of the academy at Right to Dream. The defender was an integral part of the RtD U18 team, helping them win back-to-back Gothia Cup tournaments in 2014 and in 2015.[3]
FC Nordsjælland
On 2 August 2016, it was confirmed, that Mumin had signed a professional contract with Danish Superliga side FC Nordsjælland, and joined their U19 squad.[4]
Mumin made his Nordsjælland debut on 7 August 2016, just a few days after signing with the club. Mumin started on the bench, but replaced Viktor Tranberg in the 62nd minute in a 2–1 defeat against AaB in the Danish Superliga.[5]
He was promoted to the first team squad for the 2017–18 season. After Nordsjælland sold Andreas Skovgaard in January 2019, Mumin began to play continuously.
On 15 August 2020, Portuguese Primeira Liga club Vitória S.C. signed Mumin on a four-year deal.[7][8] Mumin got shirt number 6 and made his official debut for the club in the Primeira Liga on 18 September 2020 against Belenenses SAD, playing all 90 minutes.[9]
Rayo Vallecano
On 1 September 2022, Mumin signed a four-year contract with La Liga side Rayo Vallecano.[10] Mumin got his debut for the Spanish side on 17 September 2022 against Athletic Bilbao.[11]
On 1 March 2025, Mumin sustained a cruciate ligament injury in a match against Sevilla, which was expected to keep him sidelined for an extended period.[12]
