Fortuna Düsseldorf Having scored three goals in seven games for TSG Sprockhövel while missing only three minutes, Niemiec joined Düsseldorf in May 2021, being assigned to the
reserve team in the fourth-tier
Regionalliga. On 8 February 2023, Niemiec made his professional debut in the
DFB-Pokal round of 16 away to
1. FC Nürnberg. He came on as a
substitute in added time for goalscorer
Dawid Kownacki with Fortuna winning 1–0, but they conceded an equaliser and the game went to
extra time. In time added onto extra time, he was fouled by opponent
Florian Flick, who was
sent off. The game went to a
penalty shootout, in which he was the only player to miss, his attempt being saved by FCN
goalkeeper Peter Vindahl Jensen. Four days after his cup debut, Niemiec played his first
2. Bundesliga game, again as a substitute. He
assisted the second goal of a 2–0 win at home to
SV Sandhausen, scored by
Rouwen Hennings. He played 12 games in his
first league season, scoring once on 24 February to conclude a 3–1 win over
Eintracht Braunschweig at the
Merkur Spiel-Arena in his third match. In the summer of 2023, Niemiec wanted to transfer to a club in the
3. Liga due to a lack of playing time, but his move did not come to fruition. On 5 December, in the
last 16 of the cup, he came off the bench with five minutes remaining and scored both goals of a 2–1 win at
1. FC Magdeburg; his contributions earned the club €1.7 million in prize money. Fortuna came third in the
2023–24 2. Bundesliga and contested the promotion/relegation playoff against
VfL Bochum, surrendering a 3–0 away win from the first leg as the game went to penalties; Niemiec came on as a substitute and scored his attempt while his team lost in sudden death.
Odense Boldklub On transfer deadline day, 1 September 2025, Niemiec transferred to the
Danish Superliga club
Odense Boldklub on a deal until June 2028. ==References==