Blues coach Craig Berube discusses the lineup changes he made for Game 4 and is confident that Vince Dunn could be the key against the Bruins' defense. (1:58)

ST. LOUIS -- After a 7-2 shellacking from the Boston Bruins in Game 3 of the Stanley Cup Final, the St. Louis Blues are making lineup changes for Monday night's Game 4, trailing the series 2-1.

Defenseman Vince Dunn, who has been out of the lineup after taking a puck to the face in Game 3 of the Western Conference finals against San Jose, returns to the team's third defensive pairing with Carl Gunnarsson, replacing Robert Bortuzzo.

"I just wanted to feel myself getting used to the speed of things. The more I practiced, the more I felt I was catching up," said Dunn, 22, a smooth-skating defenseman who had seven points in 16 playoff games. "It's hard to watch, not being a part of these games."

Coach Craig Berube thinks Dunn can be a key to breaking out against the Bruins' disruptive defense.

"He moves the puck as good as anybody on our team from our own end out transition-wise, and Dunn has the ability of doing high-end things in the offensive zone sometimes. Not all the time, but there's just times where he can do things that wow you a little bit and make a great play, or score a goal from nothing. He can make something from nothing a lot of time in those areas," he said.

At the forward spot, the Blues shuffled three of their lines. Most dramatic was the elevation of Zach Sanford from the fourth line in Game 3 to the second line with center Ryan O'Reilly and winger David Perron.

"I think it can give us a nice spark. He had a nice game in the last one. We've played together multiple times during the year. It's a good fit. We need something to generate a little bit more 5-on-5," said O'Reilly.

The duo played with rookie forward Sammy Blais in the first three games of the series. O'Reilly has just one even-strength assist and one on the power play against Boston, while Perron has been held scoreless.

"At times, we're getting the looks that we need, but we're not maintaining enough. It's too much of a roller coaster. If the plays are there, we make them. I think Zach is really good at using his size to make plays around the ice," O'Reilly said.

Blais was dropped to the third line with Tyler Bozak and Pat Maroon. Robby Fabbri, who appeared in Games 2 and 3, leaves the lineup.

Center Oskar Sundqvist rejoins the team's fourth line with Ivan Barbashev and Alex Steen, after serving a one-game suspension for an illegal hit in Game 2. He's a key penalty killer for the Blues -- and perhaps it's no coincidence that the Bruins went 4-for-4 with the man advantage in Game 3.

Also back for the Blues: goalie Jordan Binnington, who was pulled from Game 4 after giving up the Bruins' fifth goal. It was the first time in his NHL career the rookie had been yanked from a game, but his coach and teammates were quick to stamp out any speculation that there's a lack of faith in their goalie, especially when he's 6-2 after losses in the playoffs.

"In his bounce-back games, it's just his calmness and his mannerisms more than anything. I think he goes back in there and he feels real confident about himself. Early on in games a lot of times you see his puck-handling ability, and I know that he's dialed pretty well when I notice that kind of stuff," Berube said.