Goaltender James Reimer and defenceman Morgan Rielly are confirmed to participate in next month's tournament in Minsk, Belarus.
They'll be joined by Sean Monahan of the Calgary Flames, Kevin Bieksa of the Vancouver Canucks, David Perron of the Edmonton Oilers, Marc Methot and Kyle Turris of the Ottawa Senators, Joel Ward, Troy Brouwer and Jason Chimera of the Washington Capitals and Erik Gudbranson of the Florida Panthers.
Calgary Flames captain Mark Giordano, Canada's first defensive alternate for the Sochi Olympics, will not be going to the tournament due to a hand injury.
The United States named Peter Laviolette as its coach Tuesday and announced its initial 15 players. That group includes defencemen Jake Gardiner of the Leafs, Jacob Trouba of the Winnipeg Jets and Seth Jones of the Nashville Predators.
The IIHF world hockey championship runs from May 9-25.