Österberg Kalmari played in Finnish clubs Puistolan Urheilijat, Malmin Palloseura and HJK before moving to the University of Portland in 2000. Kalmari returned to HJK to play in the inaugural UEFA Women's Cup in 2001–2002. HJK reached the semi-finals, and then she moved back to the United States to play with Boston Renegades in the W-League. In 2002, she moved to Swedish Damallsvenskan club Umeå IK, where she won the UEFA Women's Cup two years in succession. Österberg Kalmari also played for Djurgården/Älvsjö in 2005 and 2006, before moving to AIK in 2007.