Marcus Mathisen

FC Copenhagen

In the spring 2015, Mathisen trained with the F.C. Copenhagen first team and played several matches for the reserve team. He was in the squad for the 2015 Danish Cup Final, but remained on the bench for the whole match. Three days later, Mathisen made his first team debut, when he replaced Daniel Amartey in a 2–0 loss against FC Midtjylland. Mathisen was permanently promoted to the first team squad on 13 July 2015.

Halmstads BK

On 20 November 2016, Mathisen scored two goals in the last play-off leg against Helsingborg at Olympia, which meant 3–2 on aggregate and advancement to 2017 Allsvenskan.

Falkenbergs FF

It was confirmed on 10 December 2018, that Mathisen had signed with Falkenbergs FF until 2020.

IK Sirius

On 4 January 2021, Mathisen joined IK Sirius as a free-agent; he signed a contract until 2023.

Wehen Wiesbaden

On 26 June 2023, Mathisen moved on a free transfer to 2. Bundesliga club Wehen Wiesbaden.

Magdeburg

On 26 June 2024, Mathisen joined 1. FC Magdeburg in 2. Bundesliga.

St. Pauli

On 26 June 2026, Mathisen signed with St. Pauli.

As of match played 30 August 2026

Copenhagen

Danish Superliga: 2015–16 Danish Cup: 2014–15, 2015–16