In preparing for the Rangers’ matchup with the Senators at Ottawa, head coach Gerard Gallant made a point to address the feeble starts to games that have troubled his team since the Blueshirts returned from their two-week layoff — and even cropped up earlier in the season.

The Rangers have been a second- or third-period team for much of 2021-22, which has allowed them to rally from lackluster first periods on more than one occasion. The past two games, however, have been so tight that a better performance in the opening 20 minutes surely would’ve made a difference.

It evidently got to the point at which Gallant felt the need to meet with his players about it.

“It’s just doing things the right way,” he said after practice Saturday before the Rangers got on a plane to Ottawa. “It’s mentally getting prepared for those games. For whatever reason, recently — couple games before the break, couple games after — we just have to get off to better starts. I think it’s all mental. Get yourself prepared and do your workouts and focus on your first shift, and things will take care of itself.”

The Rangers have been outshot in the first period in eight of their last 10 games. Surprisingly, they lost the two games in which they had the shot advantage after 20 minutes — against the Wild and Blue Jackets. In the other eight games, the Rangers went 6-2.

The Rangers’ goal differential by period this season isn’t actually that glaring. They have a plus-1 differential in first periods, having scored 35 goals and given up 34. With 49 second-period tallies and 47 against, the Rangers are plus-2 in the middle frame this season.

That changes in the third period. They have given up the third-fewest goals in the third period (40), while also owning a telling plus-20 goal differential, with 60 scores in final frames.

“If we want to be the team we think we can be, it’s 60 minutes,” Ryan Strome said. “The last two games we’ve seen the last 40-45 minutes how good we can be. But obviously, it’s not good enough in the NHL. It’s got to be 60 minutes. The starts are obviously very important. You can dig yourself a hole. We were fortunate it was only one goal last game [against the Red Wings], but if it gets any more, it’s tough to get out of that.

“I think it’s just mental preparation from the group, I don’t think it’s a lack of care or anything like that. It’s just being dialed in and ready to go. We addressed it and we can go out there, have a couple good shifts early and get into it.”

Since the Rangers are aware of the slow starts, Strome said, they should be able to focus on it. The 28-year-old winger noted they have to be on the same page from puck drop.

“It’s more just a readiness thing and each person has to kind of take accountability of their own starts and be ready to go,” he said.

The Senators, who are in sixth in the Atlantic Division entering the game Sunday, a makeup of the postponed Nov. 20 match, should be an ideal opponent for the Rangers to break their streak of blah first periods against. Not only are the Senators without a few young forwards, but also they will be missing their top defenseman in Thomas Chabot, who was put on injured reserve after he was shaken up by a massive hit from the Capitals’ Tom Wilson.

“Young, talented team that works their tails off every night,” Gallant said of the Senators. “You go into Ottawa and think you’re going to get two points that’s going to be easy, you’re second guessing yourself because that’s a real good hockey team. DJ Smith’s got them playing a real good style and they still got some key guys out of their lineup, some of those young players who are out, but that’s it.”