Canada's Shane Doan, left, celebrates teammate Steve Stamkos' goal versus Belarus at the world hockey championships. ((Jacques Boissinot/Canadian Press))

General manager Doug Armstrong plans to be picky when he invites two players from teams exiting the first round of the Stanley Cup playoffs to join his undefeated Canadian squad at the world hockey championship.

The betting line is Armstrong will bolster his lineup with a forward and a defenceman for the all-important second week of competition, which includes qualifying for the medal round.

"We want to take our time and bring the right people we feel can help fit in to what we have and not just react too quickly," Armstrong said Monday as he watched his players practise in preparation for Tuesday's game against winless Slovakia.

"You look at that San Jose-Anaheim series [which Anaheim leads 3-2] and there is a plethora of great Canadian talent on those teams," said Armstrong.

"So there is a lot of options and we do not want to make a decision too early that there might be a player there who might be a better fit for what we need," added Armstrong, vice-president of player personnel with the NHL's St. Louis Blues.

On Thursday, Armstrong added Blues goaltender Chris Mason to the world roster after St. Louis was swept in four straight games by the Vancouver Canucks.

The Canadians didn't need reinforcements in a 6-1 win over Belarus and they hardly worked up a sweat in a 9-0 thumping of Hungary.

Rick Nash of the Columbus Blue Jackets declined an invitation to come to Switzerland after being eliminated by the Detroit Red Wings, but Chris Mason of the St. Louis Blues flew overseas right away.

Canada thumping weaker teams

The first leg of the 2009 world championship lived up to its tradition of having Canada face much weaker teams, and the Slovaks, based on their play so far, should be easy pickings.

The game against struggling Slovakia signals the end of the opening round of the 16-team tournament, after which 12 teams advance to the qualifying round followed by the quarterfinal.

Canada's goal in qualifying is to finish as the No. 1 seed in its side of the competition and play the fourth seed from the other group in the always unpredictable quarterfinal cross-over game.

"You want the best possible matchup you can get," said Armstrong.