A potential goaltending battle between old friends-turned-foes is set for Saturday as Jeremy Swayman’s Boston Bruins host Linus Ullmark’s Ottawa Senators in the Atlantic Division rivals’ first meeting of the season.

One of the NHL’s best duos over three seasons was broken up when Boston traded Ullmark to Ottawa in July. Now, a head-to-head clash between Ullmark and Swayman is likely on deck after their partners — Boston’s Joonas Korpisalo and Ottawa’s Anton Forsberg — started Thursday.

Swayman is carrying the No. 1 load after signing an eight-year, $66 million deal to remain in Boston last month, but the partnership that helped cement his current status will never be forgotten.

“It just shows what kind of character (Ullmark) has — to pick up those guys around him,” Swayman said. “It still hasn’t hit (being rivals now). It still feels like I have his presence around here and the traditions that we had still live on. … We’re brothers for life.”

Boston has won three of its last four games, with Swayman — the owner of a 4-5-1 record and an .894 save percentage for the season — starting two consecutive prior to Thursday. His 23-save effort Sunday against Seattle marked the Bruins’ second shutout in as many days.

On Thursday, Korpisalo made 34 saves, including four in overtime, in the Bruins’ 4-3 win over the Calgary Flames. Brad Marchand clinched it, scoring his franchise-record 21st career overtime goal with 20 seconds remaining.

“I think we’re building a little bit of confidence with every game, in our system and the way that we need to play,” Marchand said.

Bruins coach Jim Montgomery hopes that his captain’s effort can trickle to the rest of the team.

“I thought he was on top of his game, skating well,” Montgomery said. “His second and third effort, it needs to become contagious on our team because he’s a great leader.”

Ullmark has struggled out of the gates in Ottawa, dropping back-to-back decisions to slip to 2-4-0 with an .892 save percentage. His Senators team has also lost two in a row following a 4-2 Thursday defeat to the New York Islanders, which was only their second in seven home games this season.

“I don’t know (if my game) is in a good place or a bad place,” Ullmark said. “All I know is that it’s going to be exciting for me to go in there (Saturday) and battle my heart out and try to make the most of it, enjoy it … because at the end of the day, the sun will rise tomorrow. It’s going to be a new hockey game, the game’s going to be played in Boston and I’m happy about that.”

Forsberg made 21 saves and Tim Stutzle assisted on goals by Nick Jensen and Drake Batherson, but the Islanders’ 3-0 lead was too much to overcome.

“Our execution was off, some of our decision-making with the puck wasn’t good enough (early),” Senators coach Travis Green said. “When we figured that out, our game picked up.”

Batherson is in a three-way tie for second on the team with six goals, matched by Stutzle and Massachusetts native Adam Gaudette. Only Brady Tkachuk has more, with seven.

The 2018 Hobey Baker Award winner at Boston’s Northeastern University, Gaudette entered this season with just two NHL games under his belt since 2021-22, but he had a run of six goals in five games that ended this week.

The emergence of players like the 28-year-old Gaudette lower in the lineup has helped to create key depth.

“When you have four lines and you can get some rotation and they’re playing well — a lot of teams strive for that,” Green said.