Trent Frederic swaps in for injured Jake DeBrusk for Bruins

One game into the new NHL season, and two points tacked up in the win column, and sure enough, it’s time for the Bruins to change things.

It’s hockey, and as certain as the net is a 24-square-foot target and the puck a chunk of vulcanized rubber, injuries forever mess with success.

Jake DeBrusk, who appeared to jam his right wrist or forearm Wednesday night in Washington, sat out the third period of the 5-2 win over the Capitals. The No. 2 right wing will continue to have his meter flashing “Off Duty” Saturday night with the Coyotes in town, opening up a spot for Trent Frederic to slip into the lineup for the home opener on Causeway St.

DeBrusk’s exit — his projected time on the sideline yet to be determined — triggered three moves, including coach Jim Montgomery’s decision to go with Frederic, the strapping wing/center who sat out the opener after his ho-hum training camp.

Another move, initiated when DeBrusk went down in Washington, shifted Craig Smith up to the second line, where he’ll ride again with team captain Patrice Bergeron at center and Taylor Hall at left wing with the Desert Dogs in town.

Finally, newcomer A.J. Greer, who made his Bruins debut at left wing on a No. 3 trio with Charlie Coyle and Smith, now will shift over to the right side spot vacated by the promoted Smith.

Greer, who fires from the left side, will be dealing on his off wing, after registering three shots Wednesday night when lined up on the left side.

It was a decent first night for the 25-year-old Greer — three shots, three hits, 9:42 time on ice — but the former BU forward said after Friday’s Garden workout that he expects more of himself as a physical presence out there.

“There were some good things …” mused Greer, now in his sixth season of trying to secure steady, fulltime NHL employment. “... I feel like it was just a quiet night for me.”

It was Greer’s jam quotient, mixing in a bit of rabblerousing and goal scoring, that landed him a spot on the varsity roster out of training camp. To stick here, he’ll need to make that a trademark of his game. Despite registering the three hits, some of that spark wasn’t there, and its absence was obvious.

“I’m someone who brings energy,” noted Greer. “And I definitely brought energy at some points … some good things, nothing terrible … made some plays in the neutral zone that I’d like to have back, even if they led to nothing.”

Recognizing “patterns” of error like his mistakes in the neutral zone, acknowledged Greer, lead to necessary corrections. All standard stuff in a sport where mistakes happen on nearly every shift.

“But I want to impose myself every shift,” said Greer, focusing on where he’d like to improve most, beginning Saturday night. “I know I can angle a little more. I know I can create offensive opportunities and be reliable defensively. All in all, though, I was happy with the first step, the first game and it’ll only get better.”

Montgomery appreciated Greer’s assessment that there is room for improvement, and equally appreciated his intention to address it.

“I really enjoy the fact that he looks in the mirror and wants to be better,” noted the coach. “That’s what he wants. And seems like that’s how everyone’s wired here, with the culture set by [Zdeno] Chara and [Patrice] Bergeron … for A.J. Greer, the more that he goes north-south and uses his feet and his aggression, the better we are and the better he is.”

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Swedish defenseman Anton Stralman, signed to a one-year, $1M deal earlier in the week, has yet to clear up his visa issues and will not be available for the home opener, which will mean the same three D pairings as in D.C: Hampus Lindholm-Brandon Carlo; Derek Forbort-Jakub Zboril; Mike Reilly-Connor Clifton … Jeremy Swayman, 23-14-3 in his rookie season, will get the start in the Bruins net … Matt Grzelcyk, working his way back from offseason shoulder surgery, moved smoothly during the 40-minute workout, paired with Stralman. Montgomery expects the former BU Terrier will be ready for game action no later than next weekend, and sounds eager to get him in the lineup. “I think he’s getting closer every day,” noted Montgomery. “It’s just a timing issue, you know, getting used to some practice reps so that he’s used to timing breakouts, joining the play, transitioning to offense … just things that while you are out, your brain’s not wired that way. It’s getting muscle memory back in his game.”… Forbort piled up a team-high 23:19 TOI and a team-high six blocked shots vs. the Caps and earned an “excellent” rating from Montgomery. “He ate pucks,” said the coach. “Did a lot of effort things … it was evident … that’s why [D coach] Jon Gruden used him so much because he was killing plays, he was ending plays, and we weren’t spending much time in our own end when he was out there … Brandon Carlo and Taylor Hall each picked up a pair of minor penalties, transgressions the coach would like not to see again. “Game management … I didn’t think we needed to take two or three of those,” said Montgomery. “They are penalties. When stuff is kind of blatant, you give the refs the opportunity to make easy calls, and they made them.”... As practice wrapped up, Swayman and Linus Ullmark performed their patented goalie embrace near center ice. But this time the hug brothers sandwiched Montgomery in their embrace, with the 5-foot-10-inch bench boss nearly vanishing in the forest of pads, blockers, and gloves. “They caught a joke on me,” said a smiling Montgomery. “I said, ‘We need some shooters in these nets, stop hugging it out.’ And they said, ‘Do you want a hug?’ And so, I don’t say no to my kids, so I’m not going to say no to my goalies.”

Kevin Paul Dupont can be reached at kevin.dupont@globe.com.