Rob O’Gara has been coming to Bruins camp for a long time. A veteran of five development camps, the 2011 fifth-round pick graduated from Yale this year and arrived at Thursday’s opening day of Bruins rookie camp in better shape than ever, with high hopes of making an impact on the blue line.

Like Boston University graduate and fellow defense prospect Matt Grzelcyk, O’Gara now has four years of college experience to call on, but it might be the graduate work he did this summer that counts the most.

O’Gara graduated from Yale (national champion as a freshman, 4 goals and 8 assists in 30 games in his senior season, two-time All-American) and in other summers, he would go home to Massapequa, N.Y., and work out there. This summer, he hooked up with Brian McDonough’s Edge Performance Systems in Foxborough, joining a group of local professionals such as Brian Boyle and Jimmy Hayes, as he built his body and his resolve.

Watching the guys who were already professionals go about their routines was eye-opening.

“I was working down in Foxborough with Brian McDonough and skating with those guys and really sort of immersing myself in that pro lifestyle,’’ O’Gara said. “It’s something I’ve never experienced before.

“I feel so much better now than I did this time last summer, and incrementally the summer before that. I feel like I’ve put myself in a place where I’ve worked my butt off and we’ve just got to see what happens.’’

At 23, the 6-foot-4-inch O’Gara has worked hard to put some pounds on his lanky frame. He’s at 215 and still trying to build more. This summer, he got a good look at the bodies he will have to go up against.

“These guys are very competitive and they’re all pushing each other,’’ he said. “It was so helpful. These guys know what it takes to play at the level I’ve dreamed about playing. It really made for a summer where I feel like I got stronger and I got better.’’

For the first time, O’Gara said, he had to think only about hockey.

“I didn’t have worry about school,’’ he said. “All I had to worry about was working out, skating, and cooking.

“I’m sticking to three things, and I’ve become very good at them, including my dad’s meatball recipe. Those are very good. I’m very proud of those.

“That’s the lifestyle now. I don’t have to worry about what classes I’m going to take in the fall, I don’t have to worry about getting the degree, getting Mom the diploma, it’s more this is my job now.’’

Thursday’s off-ice testing was the start of a new chapter for O’Gara.

“It doesn’t feel like that first development camp did,’’ he said. “I was very much a deer in the headlights back then.

“It’s very high-energy, everyone’s very excited. We’re all just really raring to get on the ice. We want to get going with that.’’

There were some new wrinkles.

“We did two 300s [runs] instead of three,’’ he said. “So you’re not pacing yourself, you’re going as hard as you can go.’’

That might be an apt description of the necessary approach to the rookie tournament in Buffalo, the Prospects Challenge, a round-robin event featuring prospects from the Bruins, Devils, and Sabres that will take place this weekend at HarborCenter in Buffalo. The Bruins have seven defensemen signed to NHL contracts, but O’Gara is among a group of prospects, including Grzelcyk, Brandon Carlo, and Jeremy Lauzon, who are expected to challenge for a position with the big club.

“The older college players, they have to hit the ground running,’’ said Bruins general manager Don Sweeney. “They’re more mature, they should be comfortable in what they bring to the table.

“Once you get by the new experience of being a pro, that should go by pretty quickly. I think rookie camp represents a great opportunity for that. Then you get into the main camp and see where you are in the overall master plan.’’

“I expect both those guys [Grzelcyk and O’Gara] to be at the forefront in rookie camp and main camp.’’

At Yale, O’Gara played two games a week in a 30-game season. Whether he plays with Boston or the Providence Bruins, it will be a 76- to 82-game grind.

“It will definitely be an adjustment,’’ he said, “in terms of how you feel it out and how you treat your body and recover. I think leaning on the older guys who have been through it before will definitely be helpful.

“And I think the work of the summer — that’s why you do that, in order to last the whole season.’’

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Sweeney announced that executive director of player personnel John Ferguson will also serve as general manager of the Providence Bruins. Ferguson is entering his third season in the Bruins organization.

The Bruins also hired Sean Jordan as head physical therapist, Ansel Garvey as assistant athletic trainer, Kenneth Pitts and Mike Macchioni as sports performance coaches, Ryan Hardy as a US amateur scout, Victor Nybladh as a European amateur scout, Matt Lindblad as a professional scout, and Brett Harkins as a part-time collegiate scout. Former strength and conditioning coach John Whitesides has transitioned to a new role of director of health, fitness, and wellness. In addition, assistant athletic trainer Derek Repucci has been relieved of his duties.