Organizers specifically hope that people will engage with social workers, nurse practitioners, and substance use counselors at the center, which will host recovery sessions and group-based trauma therapy. It will also function at times as simply a warm and dry place out of the elements, somewhere where someone can play a game of Scrabble if they so choose. Walk-ins are welcome.

“We could build them a mansion — if you don’t give them the right support, they’re not going to be able to sustain it,” Frederica M. Williams, president and chief executive of Whittier Street Health Center, said Thursday during a tour of the new facilities.

Already, outreach teams from Whittier go to Mass. and Cass, the area around the intersection of Massachusetts Avenue and Melnea Cass Boulevard that is the heart of the region’s opioid and homelessness crises, offering support services three times a week, and they will help transport people to the new center.

“There are people who want to get out of their situation but they need the support,” Williams said.

The opening of the new center in Roxbury is part of a broader, 11-point plan Mayor Michelle Wu announced earlier this year to address the crisis at Mass. and Cass by focusing on housing, health care, and public safety programs.

Included in that plan was a pledge for city authorities to work with health care organizations to create daytime engagement centers in different neighborhoods, connecting people to social support services away from the Mass. and Cass area, where they are regularly tempted by an open-air drug market.

For years, most of the city’s services for homeless people and those suffering from substance abuse have been concentrated in and around Mass. and Cass: The area hosts two homeless shelters and at least one methadone clinic, as well as the Boston Healthcare for the Homeless Program and Boston Medical Center recovery programs.

The day engagement center at Whittier appears to be a step toward decentralizing services from that area, although some neighborhood leaders would prefer to see such a site farther away from Mass. and Cass. In heavy traffic Thursday morning, it took 10 minutes to drive from the new Whittier center to the heart of Mass. and Cass.

“We were hoping we would get a greater geographic distance from Mass. and Cass,” said Steve Fox, chairman of the South End Forum, an umbrella organization for neighborhood groups in the area.

Fox said there is concern that Whittier, as well as another new initiative in Back Bay, where Boston Living Center now offers harm reduction services, will simply become satellites of Mass. and Cass rather than distinct service locations.

“At this point, it’s wait and see,” he said.

The city has at times struggled to maintain safety at its original engagement center at Mass. and Cass. Earlier this year, a rash of brazen, daytime stabbings there prompted authorities to shut down the facility. It later opened under a changed schedule and capacity level. Last month, it served a little more than 200 people per day.

At the Whittier location, officials appear to be taking precautions. There are armed guards, and people are asked to store their items in lockers outside. Metal detectors frame the entrances. There are two rooms for the public: one for men, one for women. The staff is trained in how to use Narcan, which is a medicine used to reverse an overdose.

“We want to create a safe place for people,” Williams said.

Late Thursday morning, the daily struggles of Mass. and Cass were evident to passersby. On Southampton Street, a crowd of dozens who were seeking, doing, and selling drugs took up one lane of street traffic. Tarps set up as shelters were lashed to fences on the sidewalk, where a few tents had also been erected. Boston police estimate about 200 people congregate on the street every day.

Smoking a cigarette across the street from that scene, Robert Newell, 60, thought people in need of help will use the new Whittier facility. Newell is back on the streets after relapsing three months ago and said he was on a waiting list for housing.