ST. LOUIS — John Moore is ready for his closeup and the chance to make an impact in the Stanley Cup Final.

Moore is expected to replace injured defenseman Matt Grzelcyk in the Boston Bruins’ lineup for Game 3 at the St. Louis Blues on Saturday night. Grzelcyk is in concussion protocol and didn’t travel with the team, and Moore took his place in practice Friday alongside Connor Clifton.

“This is why you train, why you prepare, why you take care of yourself,” Moore said. “When you’re called upon, it’s time to do your job.”

The series is tied 1-1.

Moore for Grzelcyk is one of a couple holes being filled with injuries and a suspension affecting the plans for coaches Bruce Cassidy of the Bruins and Craig Berube of the Blues. Boston first-line center Patrice Bergeron and Blues first-line winger Vladimir Tarasenko are confirmed to play in Game 3 after each one missed practice for maintenance, but the lineups have to change slightly.

The Blues will be without important grinder Oskar Sundqvist after their only active player with a Cup ring was suspended one game for boarding Grzelcyk and knocking him out of Game 2 on Wednesday night. Zach Sanford is expected to go in the lineup for his first playoff action since the first round, though Berube wouldn’t confirm that and said injured forward Robert Thomas was a “possibility” to play.

Neither one can replicate exactly what Sundqvist does for St. Louis.

“Does a lot of good things for us on both sides of the puck,” Berube said. “Good penalty killer, center, wing, great defensively and has produced for us, too. Good player.”

Sanford hasn’t played since Game 3 of the Winnipeg series April 14. That’s an even longer layoff than Blues winger Robby Fabbri, who replaced Thomas in Game 2.

“The guys who haven’t been playing have done a good job of holding each other accountable,” Sanford said. “We’ve been skating, working out. It’s a little different when you get into a game.”

Moore knows all about this stage after playing for the New York Rangers in the 2014 Cup Final against Los Angeles.

“It’s definitely one of those things you can take a deep breath, make sure you’re focused,” Moore said. “There are a lot of distractions at this stage of the playoffs. If anything, I feel I’m more mature to handle that and be focused on my job.”