During his third OHL season with the Saginaw Spirit, Pyatt was chosen to represent Team Canada at the 2006 World Junior Championships in Vancouver, helping them to a gold medal as the tournament host country. The next year, he returned to Team Canada for the 2007 World Junior Championships in Leksand. Pyatt helped Canada defeat Russia 4–2 in the final to capture his second straight gold medal (as well as Canada's third consecutive gold medal of a five-year run).