Beaulieu, the No. 17 pick in the 2011 NHL Draft, played five games earlier this season and had one assist. He made his NHL debut last season and had two assists in six games.
"I've matured a lot since last year," Beaulieu said. "[Last year] I was running around everywhere, and you can't do that anymore once you are out of juniors. I made adjustments and feel like I can compete at a higher level now."
Nattinen will be making his NHL debut Saturday. The 23-year-old was a third-round pick (No. 65) by the Canadiens in 2009 and has five goals and 11 points in 37 games this season with the Bulldogs.
"I want to bring speed, size and a good defensive game to the team. Hopefully, I'll also be able to create some offense," Nattinen said.