Tancredi played for the under-19 provincial team and Burlington Sting club program. She helped the Burlington Sting win the Canadian title and Ontario Cup and was named the Most Valuable Player (MVP) of the Burlington Sting in 1999.
In 2003, Tancredi was named First Team All-American, Second Team All-American, NSCAA Second Team All-Region, Big East Defensive Player of the Year, and First Team All-Big East Conference. She was a finalist for the MAC Hermann Trophy.
Tancredi made her debut with Canada as a central back, starting in all five games of the 2004 Olympic qualifying tournament in Costa Rica. Canada had 6–0 wins over Jamaica and Panama, two wins over Costa Rica (2–1, 4–0), and a 2–1 loss to Mexico that cost the Canadians a spot at the Olympic Games. Tancredi had previously been invited to play with the Canadian national team at the 2000 Algarve Cup in Portugal.
Tancredi competed for team Canada in two world cup final tournaments: 2007 and 2011; and two Olympics: Beijing 2008 and London 2012. At these tournaments, she played in 14 matches and scored 6 goals. She and her teammates won bronze medals at the London Olympics.
In 2009, Tancredi played for the Saint Louis Athletica in the Women's Professional Soccer league. In 2010, she joined the Vancouver Whitecaps FC in the W-League and led the team with six goals and two assists, The team was undefeated in the regular season and had a spot in the W-League's final four.
In 2011, Tancredi was a member of the Piteå IF in Sweden. In 2012, she played with the Swedish team Dalsjöfors GoIF. In 2014, she was allocated to the expansion Houston Dash by Canadian national team coach John Herdman, but was traded to the Chicago Red Stars for fellow Canadian international Erin McLeod before the Dash's expansion draft.