It was considered unlikely that Rielly would be loaned to Canada for the tournament, which begins Dec. 26 in Malmo, Sweden, though a stretch of three straight games in the press box made it something of a debate.
The defenceman has appeared in five straight games since then, and Toronto ended the speculation by confirming the 19-year-old will be sticking around.
Rielly has a goal and nine assists in 27 games this season. He was the No. 5 pick in the 2012 draft and made the team out of training camp.
Had he been loaned to Team Canada, Rielly was considered a candidate to be team captain.