That's in large part because the Maple Leafs' No. 1 line of Marner, Matthews and Zach Hyman has yet to be scored on in the best-of-7 series, which Toronto leads 3-2 heading into Game 6 at Montreal on Saturday (7:30 p.m. ET; NBCSN, CBC, SN, TVAS).
With a victory, the Maple Leafs would advance to the second round against the Winnipeg Jets.
"I can understand why we want the goal production to inflate and grow," Maple Leafs coach Sheldon Keefe said Friday. "They do as well. But they're contributing very positively to the success we've had throughout the series.
"If you score five or six goals but you give up five or six goals, you haven't really helped the team. These guys haven't given up anything despite playing the most minutes, despite spending a lot of a lot of time against really good players and really good matchups, despite having to take face-offs in their own end, which a lot of top lines don't necessarily do."
Marner led the Maple Leafs and finished fourth in NHL regular-season scoring with 67 points (20 goals, 47 assists) in 55 games. Matthews was second on Toronto and fifth in the NHL with 66 points (41 goals, 25 assists) in 52 games, and won the Rocket Richard Trophy as the League goals leader.
Matthews' lone goal in the series came when the center scored in a 5-1 victory in Game 2. Marner has yet to score, but his four assists are tied for the Toronto lead with forward Alex Kerfoot. Hyman, who missed the final 11 games of the regular season with a knee injury, scored his first goal since April 13 in the Maple Leafs' 4-3 overtime loss in Game 5 on Thursday.
"They've taken on a lot, and they've played very well for us," Keefe said. "It's just a matter of time. If they keep getting those chances, really think they're going to fall in."
Matthews said the lack of goal production does not reflect how the line has played.
"I think we're hunting pucks good, trying to stay above them, forcing turnovers and just trying to attack them as much as possible," he said. "I think we just want to continue to do that.
"We're getting chances, continue to bear down and try to capitalize on some of these opportunities. But I think we want to continue to play the way we've been and just continue to give our team momentum."
Matthews leads Toronto in shots during the playoffs with 25, followed by Hyman (16), forward William Nylander (15) and Marner (14).
Keefe said Matthews and Marner have received more attention than usual from defenders in the absence of two of the Maple Leafs' top six forwards: center John Tavares (concussion, knee) and Nick Foligno (lower body). Nylander has helped pick up the offensive slack by scoring seven points (four goals, three assists) to lead Toronto and is on a five-game point streak, but Keefe says it's only a matter of time before the Matthews line starts producing more as well.
Keefe credited Canadiens goalie Carey Price and the Montreal defense for their play against Matthews but said the coaching staff is examining ways to create more space for him in the offensive zone.
"We'd like to find a way to get Auston some cleaner looks at the net," he said. "A lot of the best looks have come with Mitch and Hyman, and Auston hasn't been able to get as many clean looks at the same time. He's drawing a lot of attention and focus there. So that's something for us to continue to look at."
