Jansson was the captain of AIK during the season 1994-1995. His move to rival club Djurgårdens IF in 1996 was not a popular one amongst fans especially for a hooligan firm associated with AIK called Firman Boys. After leaving the club Jansson received death threats and had his door painted orange (the color of Firman Boys) with the text Judas. One of the reasons for him subsequently leaving Djurgårdens IF in 1997 for Norwegian club Stabæk Fotball was because of this intimidation. Even after moving to another country and securing a protected identity he would still go on to receive threats. [1]
After retiring, Jansson was the general manager at Helsingborgs IF between 2008 and 2014. In 2015, he was appointed head scout at F.C. Copenhagen,[5] but left a year later. On 28 April 2017, Jansson was appointed director of football of Hammarby IF,[6] before stepping down in 2023.[7][8]
On 14 June 2023, he was appointed sporting director of AC Omonia. He was dismissed from his role after only 7 months in charge, along with the managing staff he appointed, after accusations from the club president that Jansson was not doing his job and was treating the appointment on Cyprus as a vacation. Jansson denied wrongdoing, pointing to his years of experience and the fact that he has sold players for 50-60 million euros as evidence that he takes his jobs seriously. [9]