In February 2015, Swolfs signed with Mechelen, who had scouted him in the youth department of Club Brugge. There, he became fourth in the goalkeepers depth chart behind Jean-François Gillet, Colin Coosemans and Anthony Moris. He did not make an official appearance during his three years at Mechelen, but Swolfs impressed to such a degree with the reserve team that he secured a move to Gent, where he signed in January 2018.[2] At Gent, he became third goalkeeper on the depth chart behind Lovre Kalinić and Yannick Thoelen.
To allow Swolf to gain playing experience, Gent loaned him out to Waasland-Beveren in the summer of 2018.[3] There too, however, he became backup, this time to Davy Roef and Kevin Debaty. He only made his debut in the Belgian First Division A on 11 May 2019, when manager Adnan Čustović started him in the second play-off match against Cercle Brugge. Swolfs only allowed one goal and helped Waasland-Beveren to a 2–1 win. On the final matchday of the season, he also made a start, this time against Royal Excel Mouscron.
On 31 May 2019, Dutch Eerste Divisie club Telstar signed Swolf on a free transfer from Gent. He signed a one-year contract with the option of an extra year with the club.[4] He immediately became the starting goalkeeper. One year later, Swolf moved to division rivals Dordrecht.[5]
In January 2021, Swolfs abruptly announced his retirement from football after a match against Volendam to focus on a career as a financial adviser.[6][7]