General manager Jay Feaster announced that Tuesday, explaining the organization's case for keeping the 19-year-old centre in the NHL during the event.
"We have spent a great deal of time discussing and debating the pros and cons of the situation in the context of what is best for Sean’s continued professional development as a hockey player, as well as what is in the best interests of our team, our fans, and our organization," Feaster said. "We have concluded that in light of the prominent role Sean has played on our team to date, and the role we project he will continue to play once he returns from his injury, that Sean will remain with our hockey club."
Monahan, the No. 6 pick in June's draft, has nine goals and six assists in his first 24 games for Calgary. He's currently out with a fractured left foot, but it was Hockey Canada's hope that the Flames would let him go to the world juniors as something of a rehab assignment.
Instead, he'll be staying with Calgary for the duration.
The IIHF World Junior Championship begins Dec. 26 in Malmo, Sweden.