Tyrell began his junior career after being selected in the 5th Round, 97th overall in the 2004 WHL Bantam Draft. The native of Airdaire, Alberta played just 1 game in the 2004-2005 season for the Cougars registering zero points and 2 penalty minutes. In 2005-2006, Tyrell played his first full season in the WHL posting 7 goals and 18 points along with 44 penalty minutes in 69 games. That year Tyrell also appeared in 5 playoff games going scoreless with 2 penalty minutes. Entering his draft year Tyrell was a relative unknown but he had a strong breakout season for Prince George scoring 30 goals and 56 points in 72 games to go with 51 penalty minutes. In the playoffs Tyrell tallied 1 goal and 7 points in 15 games with 4 penalty minutes. At season's end he was ranked 15th amongst North American skaters by the NHL Central Scouting Service and 30th by the Redline Report. Tyrell was selected by the Lightning in the 2nd Round, 47th overall in the 2007 NHL Entry Draft. He appeared for Canada in the Canada/Russia U20 Super Series in the summer of 2007. In 2007-2008 Tyrell was the best player on a cellar dwelling Prince George team posting 25 goals and 65 points in 68 games with 47 penalty minutes and a -26 rating.
At the end of his junior season with Prince George in 2007-2008, Tyrell signed an amateur tryout contract with the Norfolk Admirals. In 11 games with the Admirals, Tyrell scored 1 goal and 6 points with 6 penalty minutes and a +1 rating. Tyrell was ineligible to play in the AHL in the 2008-2009 season so he returned to Prince George of the WHL where he posted 19 goals and 40 points in 30 games with the Cougars. He was named to Team Canada for the 2008 U20 World Junior Championships and was slated to play on the team's top line, but suffered a season ending knee injury in a pre-tournament exhibition game against Sweden.
