Alex Harvey, who was sixth overall in the seven-race event on Thursday, finished 34th to slip back to 16th place overall. His teammates Ivan Babikov and Devon Kershaw were 40th and 41st on Saturday to fall to 35th and 36th overall as the Canadians struggled to find the right combination of wax.
"Today unfortunately the skis could have been better, " Canadian coach Tor Arne Hetland explained. "It was tricky conditions and we just couldn't keep up with the rest right from the start. We are going to meet and review things and figure out what happened."
Germany's Tim Tscharnke won the stage in a sprint over Kazakhstan's Alexey Poltoranin, with Switzerland's Dario Cologna, third.
Petter Northug Jr. of Norway held onto the overall lead despite finishing the stage in 21st place. Northug holds a 13.1 second advantage of Martin Johnsrud Sundby, also of Norway, with one stage remaining Sunday. Sweden's Calle Halfvarsson is another 26 seconds back in third.
The Tour de Ski began Jan. 3 in Oberstdorf, Germany and passed through Val Mustair, Switzerland and Toblach, Italy before heading to Val di Fiemme.
The final stage Sunday is a 9k uphill pursuit up the challenging Alpe de Cermis.
Harvey, who has circulation problems in his legs aggravated by uphill climbs, will not contest the final stage, but Babikov, an excellent climber and Kershaw will race again Sunday.