Saskatchewan hockey player Mandi Schwartz has suffered a setback in her fight against leukemia.

The cancer has returned and delayed the stem cell transplant the 22-year-old was to undergo Aug. 26 in a Seattle hospital, according to the doctor who organized a donor campaign for Schwartz.

Schwartz, from Regina, played hockey for the Yale Bulldogs and also tried out for Canada's under-22 women's team.

Dr. Ted Collins, whose daughter Natasha died of leukemia, said on Schwartz's Facebook page her father Rick informed him the cancer had returned.

Schwartz, who was in Seattle preparing for surgery, must undergo chemotherapy and force the cancer into remission before she can have her transplant.

Mandi's brother is Jaden Schwartz, the No. 14 pick in the 2010 NHL draft by the St. Louis Blues. Her other brother Rylan plays for Colorado College.

Schwartz was first diagnosed with acute myeloid leukemia in 2008, but went into remission in June.