The work goes on, the cause endures, the hope still lives, and the dream shall never die.

The Bruins on Tuesday open their development camp at Ristuccia Arena in Wilmington, the annual summer waltz of the WannaB’s, still very much in need of adding skill and production to their spotty backline for the 2016-17 season (opener: Oct. 13 at Columbus). Thus far unwilling to meet trade demands he deems too high, general manager Don Sweeney has these next four days to assess who among the kids at hand (27 total) might have a shot at cracking the varsity when training camp begins in September.

“We are obviously looking for that top-four guy,’’ noted assistant GM Scott Bradley, assessing the backline as the annual entry draft drew to a close last month in Buffalo. “These guys . . . I wouldn’t rule out [someone] cracking our club.’’

The backline has been in disarray ever since the October 2014 trade of Johnny Boychuk to the Islanders, and the upper end of the D corps took another hit late last month when Sweeney & Co. bought out the final two years of Dennis Seidenberg’s deal. Other than Zdeno Chara, the Black-and-Gold roster at the moment has a dearth of top-four blue liners, spots not commonly held by the likes of the 18- and 19-year-olds who’ll be skating on Ristuccia ice through Friday.

However, 6-foot-5-inch Brandon Carlo, who turned pro last spring out of junior hockey (Tri-City Americans), is a beefier, slightly more seasoned candidate. Selected No. 37 overall in last year’s draft, he proved in junior that he can contribute here and there on offense (4-23—27 in 52 games last season), and he opened some eyes with his overall play in the spring, when he joined AHL Providence for eight games after signing his first NHL deal.

“We are cautious about rushing him,’’ Bradley said. “But he came in at the end of the year and had a good run [at Providence]. Some of us got excited about him. Again, you want to be very careful about your expectations. But we are very high on him, and we’re seeing good things. If he has a good run here over the summer and trains well, he is going to get a chance to show his stuff.

“You never rule anything out, but we just want to be patient. We are excited about the player.’’

Boston’s big addition in free agency came July 1, when ex-Blues captain/center David Backes came aboard with a five-year deal worth $30 million. A rumored offer sheet for Jacob Trouba, a restricted free agent defenseman with the Winnipeg Jets, never materialized. Sweeney said he poked around on trades, dating to before the draft, and found the market asking too much for an accomplished backliner (witness: the Oilers forced to flip Taylor Hall to New Jersey for Adam Larsson).

Until further notice then, it’s up to a kid or two, possibly from among the ranks at development camp, to grasp the opportunity. Charlestown’s Matt Grzelcyk, recently graduated from BU, made an impact with the Terriers with his skating and offense, but his lack of size (5-10, 175) could make it a challenge for him to crack the varsity.

Perhaps the prime candidate for a top-four spot, albeit in a year or two, is BU’s Charlie McAvoy, the Bruins’ top pick (No. 14) in last month’s draft. His size (6-0, 208) and style of game made him the club’s No. 1 target in the draft, but unless something unexpected develops between now and September, he sounds firmly committed to returning to Comm. Ave for his sophomore season.

“We have what we feel is the right direction we want to take with players,’’ Bradley said, speaking in general terms about the pace of development of the club’s prospects. “The player himself will determine whether he’s ready or not. If he comes in and does things we are looking for, excites the coaches . . . like the coaches say, the first day of training camp, it doesn’t matter what round you are drafted in, if you come in and play well, you’ll get a good shot.’’

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The roster breakdown this week includes 14 forwards, nine defensemen, and four goalies. One of the netminders, 17-year-old Stephen Dhillon from Buffalo, has yet to be drafted and is the sole invitee to this year’s camp . . . Top prospect Jakob Forsbacka-Karlsson will not be in camp, by mutual agreement of the BU forward and the club — in deference to his academic, family, and travel plans . . . Zach Senyshyn, one of the club’s three first-round picks, has been hindered by mono and is not likely to participate . . . Workouts on Tuesday begin at 11 a.m, then shift to 10 a.m. for the remainder of the week. All sessions are open to the public . . . This is probably the club’s final formal event at Ristuccia, where years ago a small clutch of beat reporters descended upon owner Jeremy Jacobs as the club’s annual media day came to end. Then a near-recluse, the quick-stepping Jacobs groused, “Not a second,’’ as he brushed reporters aside and made his way out the door and into a waiting limo.

Bruins Development Camp roster

FORWARDS

Jack Becker

Anders Bjork

Jake DeBrusk

Ryan Donato

Ryan Fitzgerald

Trent Frederic

Jesse Gabrielle

Danton Heinen

Cameron Hughes

Joona Koppanen

Sean Kuraly

Mark Naclerio

Zachary Senyshyn (not expected to attend due to mono)

Oskar Steen

DEFENSEMEN

Brandon Carlo

Cameron Clarke

Matt Grzelcyk

Emil Johansson

Jeremy Lauzon

Ryan Lindgren

Charlie McAvoy

Wiley Sherman

Jakob Zboril

GOALTENDERS

Stephen Dhillon*

Zane McIntyre

Malcolm Subban

Daniel Vladar

*attendance on an invite basis

Kevin Paul Dupont can be reached at kevin.dupont@globe.com. Follow him on Twitter @GlobeKPD.