Wahlstedt began his professional career at the young age of 17 when he signed with Swedish club, IFK Norrköping, in 2014. He spent two seasons with the club before making a move to Danish side, FC Midtjylland, in 2016. Wahlstedt continued to impress on the field and caught the attention of several European clubs before finally signing with Blackburn Rovers in 2020.