Patrice Bergeron continues to round into form

Patrice Bergeron participated in his third skating session with the Bruins on Sunday.John Tlumacki/Globe Staff

PHILADELPHIA — It’s trending the right way for Patrice Bergeron. The Bruins’ No. 1 center was back on the ice Sunday in Brighton for his third skating session in the last five days, and the plan remains unchanged: get Bergy ready for next Wednesday night’s season opener in Washington, D.C.

“Hopefully, he’s getting closer . . . that’s the idea,” said coach Bruce Cassidy, following his club’s workout at the Warrior Ice Arena. “I think he is, but until we see him with the group, it’s kind of hard to speculate.”

Bergeron, on the cusp of entering his 15th NHL season, is working his way from a start-of-the-season physical setback.

It has become a rite of autumn in the Hub of Hockey. Hindered the last couple of years by injuries related to core strength — including surgical repair of a sports hernia — Bergeron has yet to practice this preseason after being sidelined by back spasms on the eve of training camp.

With the Bruins in Philadelphia on Monday to face the Flyers at 7 p.m. in their sixth preseason game (4-0-1 thus far), Bergeron will remain hors de combat, leaving Cassidy with just a little more than a week to ponder the overall composition of his four lines before opening night.

The No. 1 line of Brad Marchand-Bergeron-David Pastrnak is a given, provided the center iceman in that trio doesn’t suffer a sacroiliac setback. Backs can be funny things, absent any and all sense of humor, but the 33-year old remains optimistic that he’ll be back on the job as scheduled. He would like to play in at least one preseason game (perhaps Saturday’s 5 p.m. wrapup vs. the Flyers?), but if necessary, is prepared to go into the opener without a puck primer.

“The goal is to be ready for Game 1,” he said Friday, immediately following his first serious on-ice workout, albeit as a solo skater, of training camp. “Hopefully we get an exhibition game in there in the end. So we will play it by ear. I’d like to get one, but we’re not going to push for it. We’ll see how it goes.”

Cassidy’s current computation has a second line centered by David Krjeci, flanked by Jake DeBrusk on the left and either Ryan Donato or Danton Heinen on the right. Cassidy made it clear Saturday night in Detroit — prior to a 4-3 OT loss to the Red Wings — that Donato had made the varsity roster. On Sunday, Cassidy met with the media again and openly pondered which of the two left-shot wingers would fit best on their off wing.

Now that Donato is inked in, Cassidy and GM Don Sweeney are left only to deliberate over only one roster position, be it third- or fourth-line center. Returnee Sean Kuraly will fill one of the center slots, and it could well be that veteran Daniel Winnik, ex- of UNH, fills the other. If Winnik is the pick, he first would have to come to contract terms, likely a one-year deal of approximately $700,000.

“Consistency, strong on the puck,” said Cassidy, ticking off the strengths of the 33-year-old Winnik, a training camp invitee. “He’s a guy who knows how to hang on to the puck, when to get it deep . . . that’s what I’ve seen. He can play down in the lineup [lines three and four] and understands there is some sitting involved and the need to find an energy level after sitting on the bench for five, six, seven minutes. That’s the part he brings — a level of professionalism.”

Opportunity seized

Cassidy, when talking with the media after the Sunday workout, mused that Donato turning pro last spring removed any threat he “could pull a Vesey on you.”

Jimmy Vesey, who played with Donato at Harvard, played all four seasons in Cambridge and turned pro as a free agent with the Rangers. By remaining in school all four years he no longer was obligated to sign with Nashville, the club that drafted him 66th overall in the 2012 draft.

He also shunned the Sabres, who traded for his rights once the Predators were convinced he would not sign with them.

Donato turned pro just days after completing his junior season for the Crimson. Had he played a fourth season for Harvard, coached by his dad, ex-Bruin Ted Donato, he could have signed with any NHL club in the summer of 2019.

“It worked out well for us and [Donato], said Cassidy. “He’s getting an opportunity to play, to play in Boston, but he earned that. There were no guarantees he was going to come play for us. He could have gone to Providence if we didn’t think he could cut it. So he took advantage of an opportunity.”