The rookie forward replaces Eric Staal, who Canadiens coach Dominique Ducharme said is not 100 percent.
"I found out this morning," Caufield said Monday. "Obviously it's really special. I'll tell my parents when I get out of here, so they're obviously going to be excited, and I just can't wait to get going tonight."
Caufield was a healthy scratch the first two games of the best-of-7 series, which is tied 1-1. The 20-year-old made his NHL debut April 26 and scored five points (four goals, one assist) in 10 games. He could be an asset for an offense that's scored three goals on 53 shots against Maple Leafs goalie Jack Campbell in the first two games of the series.
"We like his speed," Ducharme said. "We know he's a guy who can shoot the puck and score goals. At the same time, the two games in Toronto, we had a discussion and he was able to see the difference between what he experienced at the end of the regular season and what the playoffs are about. We feel that he's ready to get in there and he's going to be one of the 18 players skating in front of [goalie] Carey [Price] tonight and we want to be at our best."
Caufield said he learned a lot by watching the first two playoff games.
"It's obviously faster pace," he said. "You know, errors are limited, guys are playing 100 percent, doing anything they can to win each shift, and I think you've got to be patient, you've got to make the right plays while you're out there, and when you get your chances you've got to capitalize. So it's a game of inches now and I'm just here to help the team win and bring the spark that we need."
Caufield agreed to a three-year, entry-level contract March 27 after two seasons at the University of Wisconsin. He won the Hobey Baker Award voted as top men's player in NCAA Division I ice hockey this season and scored four points (three goals, one assist) in two games for Laval in the American Hockey League before joining the Canadiens.
"He's confident. He's not cocky, he's confident," Montreal defenseman Jon Merrill said. "He's sure of himself as a player and as a person, which is really refreshing to see. You know, he doesn't walk around like he's better than anyone, but he definitely walks around and knows that he can make an impact. So we're excited to see what he can do tonight and we all have the utmost confidence that he's going to come in and do a job for us."
NHL.com independent correspondent Sean Farrell contributed to this report
