In the last few seconds, the Montreal Canadiens organization announced this.
'The Canadiens have recalled forward Emil Heineman from the Laval Rocket (emergency recall). He will join the team Friday afternoon.' - Montreal Canadiens
Therefore, it is an emergency recall for Heineman, and Kent Hughes thus adds reinforcements to Martin St-Louis' lineup.
With the injury suffered by Christian Dvorak, it was to be expected, but it also seems to confirm that we will have to wait longer before seeing Rafaël Harvey-Pinard and/or Tanner Pearson in uniform again.