St. Pauli until the end of the 2020–21 season, with the option of an extension. Reginiussen made his debut for the club, coming on an 84th-minute substitute, in a 2–1 win against SV Sandhausen on 5 February 2021. He then made his first start for FC St. Pauli against Karlsruher SC on 6 March 2021 and helped the club keep a clean sheet, in a 0–0 draw. On 10 May 2021, Reginiussen announced he would retire from football after the season. International career Youth Reginiussen represented Norway levels from U15 to U19 sides. On 28 February 2006, he made his debut for Norway U-21. It wasn't until on 16 August 2006 when Reginiussen scored his first goal for the national team, in a 3–0 win against Estonia U21. Reginiussen played in his career 15 caps for the Norway U-21. During his time playing for the Norway U-21, at one point, he was captain for the U-21 side. Senior His performance for Norway U-21 led the Norwegian media calls for Manager Åge Hareide to call up Reguiniussen to the national team. In May 2008, Hareide called up Reguiniussen to the national team for the first time in his career, whilst also being called up by the U-21 side at the same time. Reginiussen made his debut for Norway on 28 May 2008 against Uruguay in a friendly match, starting the match but was fault for conceding Uruguay's second goal of the game, as they drew 2–2. He then scored his first international goal for Norway, in a 1–1 draw against Republic of Ireland on 20 August 2008. Reginiussen started two more matches for Norway by the end of 2008. During a 1–0 win against South Africa on 10 October 2009, he suffered a concussion after being contacted from the opposition player's elbow and was substituted in the 59th minute as a result. After spending almost two years away from the national team, Norway called Reginiussen for the first time in November 2011. In his tenth international match, he won the match as he scored the only goal of the match, scoring from a free kick against Thailand in Bangkok on 18 January 2012. Two years later, Reginiussen was the national team captain in his last two matches of January, both playing in Abu Dhabi against Moldova and Poland. He spent the rest of the 2014, appearing as an unused substitute. After