Yesterday, many of those same lads returned to Ristuccia wearing much different looks on their still-pimply faces.

“There’s no friends out there,’’ said 19-year-old Jared Knight, one of the club’s two 2010 second-round picks. “Everybody’s going out there and competing against one another.’’

Following physicals and fitness testing, 22 hopefuls (13 forwards, seven defensemen, two goalies) hit the ice at the Bruins’ practice rink. Earlier that morning, most of the veterans had been skating on the same surface - one the prospects are aiming to consider their full-time office sooner rather than later.

The reality, however, is that none of the hopefuls who opened rookie camp yesterday stands more than a long-shot chance at cracking the Boston roster. Not even a veteran like Benoit Pouliot has an NHL paycheck on lockdown, considering the bulk of big boys the Bruins are returning.

Perhaps in previous seasons, a high-end defenseman like Dougie Hamilton (No. 9 overall in 2011) could have graduated from junior to the NHL. But with older players such as Steven Kampfer pushing for a depth job, it’s likely Hamilton will be returning to Niagara, his junior club.

That reality isn’t dulling Hamilton’s hopes.

“I just want to come in and play my best,’’ he said. “There are a lot of good D here. But I just want to show my stuff and do what I can do.’’

While Hamilton’s likeliest 2011-12 destination is Niagara, it’s a good bet that the smooth-moving defenseman will graduate to main camp (first on-ice session is next Saturday at TD Garden) and appear in at least one preseason game.

In the previous drafts under Peter Chiarelli’s watch, the Bruins have come away with forwards with their first-round picks. This June in St. Paul, with their system lacking impact blue-line prospects, the Bruins returned with Hamilton - current NHL comparables include Jay Bouwmeester and Brent Seabrook.

So with Hamilton projecting to be a top-four defenseman, the Bruins bosses will be eager to see how the 18-year-old from St. Catharines, Ontario, competes against NHL talent.

“He’s going to be a good player,’’ said assistant general manager Jim Benning, who noted that Hamilton checked in at 194 pounds, 6 more than he weighed in July. “It’s just going to be a matter of time for him.’’

If Hamilton is the organization’s blue-line blue-chipper, Knight and Ryan Spooner are their brightest prospects up front. Knight, a 5-foot-10-inch, 198-pound winger, is more pro-ready than Spooner. Knight plays a north-south game with an emphasis on grit in front of the net, along the walls, and in the corners.

Last season, Knight scored 25 goals and 45 assists in 68 games for London. This summer, Knight participated in USA Hockey’s national junior evaluation camp, a proving ground for the 2012 World Junior Championship. Knight could push Pouliot, Jamie Arniel, and Max Sauve for one of the openings left by Mark Recchi and Michael Ryder.

“I was just a rookie last year and I didn’t know what to expect,’’ Knight said. “I was a little guy in the background. This year, I know some of the guys from playing with them. This year, I’m going to be a lot more comfortable.’’

While Knight may be closer, Spooner projects to have a higher NHL ceiling. Knight could be a third-line wing. Spooner, a clever offensive-minded center, could be a second-line pivot. Also, Spooner has less competition within the organization following the trade of center Joe Colborne to Toronto in the Tomas Kaberle deal.

Last year, Spooner was the surprise of camp. He lasted until Sept. 28, when he was assigned amid the team’s second-to-last round of cuts. Management and the coaching staff liked Spooner’s creativity and hockey sense.

This season, Spooner has dropped 2.5 percent of body fat and improved his explosive skating. The numbers say otherwise - David Krejci, Patrice Bergeron, Chris Kelly, and Gregory Campbell project to be the four centers for the season opener - but Spooner is aiming to make the big club instead of being returned to his junior club in Kingston.

“Just be confident when I’m on the ice,’’ Spooner said of his approach. “It’s kind of intimidating when you’re on the ice with guys who’ve played actual games. Just believe in yourself and have confidence.’’

The rookies practice today and tomorrow. On Monday and Tuesday, they will play games against the Islanders rookies at Nassau Coliseum. Following the games, a yet-to-be-determined number of players will be promoted to main camp. After that, it will be up to the youngsters to prompt Chiarelli and coach Claude Julien into action.

“The one thing about Peter and Claude, if a player deserves to be on the team, then they find a way to get the player on the team,’’ Benning said. “With time, that will work itself out.’’

Fluto Shinzawa can be reached at fshinzawa@globe.com. Follow him on Twitter @globefluto.