What exactly Morgan Geekie’s full identity will become for the Bruins remains to be seen. But when the B’s — already down Charlie McAvoy and Derek Forbort — then lost Pavel Zacha after the first period on Saturday, Geekie showed he’s a player who can help them win games.

With Zacha out with an upper body injury, Geekie played 17:31, his second-highest total of the season, and he notched a hard-working assist on David Pastrnak’s second goal of the game that helped seal the 5-3 win over the Arizona Coyotes.

“Obviously whenever a player of (Zacha’s) caliber goes down, it’s obviously a hit to us,” said Geekie. “But we’ve got a good group. Everyone’s going to step up, everyone’s going to play more minutes. I’m just trying to go out there and do my job and fit in anywhere I can. We have guys playing all over the place tonight and that’s just how it’s going to be some days. You’ve got to figure out ways to win in this league and that’s what we did tonight.”

When Geekie was signed in the offseason on a two-year deal with an annual salary of $2 million coming off a solid season in Seattle, the tentative idea was for him to center a third line. But 19-year-old rookie Matt Poitras popped in training camp, as did rookie center John Beecher, and Geekie found himself on the wing. And then he suffered an upper body injury that kept him out for a couple of weeks, so he’s had a hard time latching on to a defined role.

From game-to-game or — as in Saturday’s case — in-game, Geekie has bounced from wing to center and back again.

“Every once in a while I’ll get caught wondering whether I’m playing wing or center, but it’s not too bad,” said Geekie, who won eight-of-12 draws. “We have a lot of communication out there and that’s pretty good. Guys are good at working in spots and we have a pretty good system here. If everyone does their job correctly, it makes any job pretty easy. So I think if we just stick to our details and play good on both ends, it makes my job going back and forth a little easier.”

And Geekie is not overly concerned with finding a more defined role.

“I’m just trying to fit in wherever,” said Geekie. “Obviously we’re a great team. We’ve got some details to iron out but I’ve said it before. I’m just happy to be here and I’m happy to jump in anywhere I can, whether that’s tonight where I was playing a little more, or if I’m playing a little more of a shutdown role on the fourth line. I’m just happy to be here and I’m grateful I get to play every day.” …

Loose pucks

Matt Poitras got back in the lineup after sitting out Thursday’s game against Buffalo in something of a rookie load management program. Coach Jim Montgomery said he’ll get occasional nights off the rest of the way, something the coach admitted the 19-year-old wasn’t wild about.

“I think he understood but he’s really competitive,” said Montgomery. “We love him because of how competitive he is, so the competitor in him doesn’t want to take any nights off. He knows why we’re doing it. It’s for his benefit and the Bruins’ benefit and he understands that. But again, he’s a competitor, so I think he’d rather play.”

Poitras had an up and down day against Arizona. He was chiefly responsible for the Coyotes’ second goal, but he also won a battle along the boards later in the second to set up Danton Heinen for what turned out to be the game-winner.

With the B’s in lead-protection mode, he did not see a shift in the third period. He played just 8:26 in all.

“It’s valuing game management. It’s something we’ve talked to him about. It’s still lacking in his game right now. We’re paid to win hockey games and I’m going to go with the guys I think are going to win hockey games,” said Montgomery.

Had the B’s been down two goals instead up by two, we no doubt would have seen more of Poitras in the third. With help from Trent Frederic (two assists), he made a strong play to win a battle along the boards and then slip the puck through to Heinen on the game-winner.

“He hangs on to pucks so well and sees the ice so well. I try to get open and be there for support and a little pop play. He’ll find you. He’s good when he has the puck in his hands,” said Heinen. …

Jakub Lauko was a healthy scratch. Montgomery said it was a good time for Lauko, who hasn’t scored a goal in his 18 games this year, to have a reset.

“I think he has been playing well, but what we’ve seen is there’s a tail-off from the first period to the third period,” said Montgomery. “Even though he knows and he relishes his role and he’s a tremendous young man, we all need to score to feel good about ourselves. You want to contribute, you want to jump in the glass and celebrate with the Bruins fans. There’s been a couple of games where he’s had some good chances early and the intensity of how he gets those chances, which is through his checking and his tenacity on pucks, kind of fades. We want him to go 60 minutes for us.” …

Montgomery said Charlie McAvoy (upper body) remains day to day.

“There’s been significant improvement, but we’re not risking today,” said Montgomery. …

The B’s won 43 out of 60 draws on the day.