No sooner had Patrice Bergeron been nominated for a fifth Selke Award Wednesday than the heart-and-soul of the Black and Gold was ruled out of Game 4 with an upper-body injury just minutes before the opening faceoff Thursday.

So much for Bruce Cassidy having his forward lines intact; it was back to his juggling act with Riley Nash moving up once again to center the first line. The Bruins were 9-2-2 in 13 games this season with Nash between Brad Marchand and David Pastrnak. That moved Sean Kuraly up to Nash’s third-line role with Tommy Wingels dressed for fourth-line duty.

Make that 10-2-2 following Thursday’s 3-1 victory in Toronto.

“Obviously you have to make some adjustments,” Cassidy said postgame and with season-long repetition, “but we lived this for a month. Riley Nash has played that position. He’s done a good job and you gotta give him a lot of credit. It was the easiest plug-and-replace because he’s been there.”

Here’s what we learned as the Bruins — sputtering in Game 3 after cruising in Games 1 and 2 — return Saturday night for Game 5 at TD Garden and the opportunity to close out the series.

Key 2-on-1 conversions lead to clutch goals

When you need a lead, who you gonna call: @pastrnak96 ➡️ @Bmarch63 pic.twitter.com/ENXfYtHx3j

— Boston Bruins (@NHLBruins) April 20, 2018

Just 28 seconds in, Nash screened Frederik Andersen as Torey Krug launched a floater from the left point that found twine; Kevan Miller and Pastrnak assisting. Ex-Canadien Tomas Plekanec fired a one-timer from the slot to tie things at 1-1 7:15 later.

The first period ended with the Bruins going four consecutive periods without a goal from the forwards. That streak ended late in the middle 20 when Pastrnak and Marchand broke in 2-on-1 on Andersen with Marchand having more daylight than high noon at 16:55 for his 50th career playoff point and the 2-1 lead; Adam McQuaid also assisting.

Another 2-on-1 factored into the 3-1 advantage when Jake DeBrusk finished off David Krejci’s feed for the insurance goal at 4:17 of the third.

Tuukka Rask on task

https://twitter.com/NHLBruins/status/987156955616624640

“Win two at home and have Tuukka steal one in Toronto,” NESN’s Jack Edwards said midway in Game 4 about the key to the Bruins winning the series.

Rask was the difference-maker Thursday. Three split-second saves midway in the first period were followed in the second period, first denying Dominic Moore’s 2-on-1 attempt and then a Mitch Marner breakaway halfway with the Leafs outshooting the Bruins, 22-16 after two.

The 2005 first round pick of the Maple Leafs sealed the victory with nine third period saves.

“Man did he come through big,” NESN’s Barry Pederson said about the Rask effort. “He settled his team down in so many ways,” added colleague Billy Jaffe.

“You need that on the road,” Cassidy said about his goaltender. “We saw that last night with games [in other series]. Once we found our legs it was very important we not lose the second period in this building. Tuukka was very big and I thought our guys beared down in the third.”

B’s D dominates talented Leafs’ forwards

“We clogged some lanes,” Cassidy said, “and didn’t give up a lot of chances as the game went along.”

For simple reasons.

In Game 3, Miller laid an egg with a minus-3. He made his presence known in Game 4, atoning for one assist to go along with a trio of blocked shots and three big hits.

The Black and Gold defense had a huge disparity in that blocked-shot category, 27-9, led by Krug’s four blocks.

Zdeno Chara and Charlie McAvoy played at a combined plus-4.

“We’re gonna break through at some point,” McAvoy said Thursday morning.

The Bruins will need more of the same steady play against Auston Matthews and the desperate Leafs Saturday.