ORONO — Darrius Hart is in a unique position among the safeties on the University of Maine football team. He’s the only one who has ever made a tackle in a college game.

That makes Hart, a sophomore, the leader of a unit that is the biggest unknown on what should be an outstanding Black Bears defense heading into the season.

“It’s a lot more pressure, but I can handle the pressure,” Hart said during the team’s media day Friday at Alfond Stadium. “I think I played my role last year. I have higher expectations for myself this year. I’m going to make a lot more plays than I did last year.”

Hart was in on 14 tackles as a true freshman in 2014, pressed into starting duty late in the season after Davonte Burke suffered a knee injury. Burke, a ferocious tackler, blew out his other knee over the summer and will miss this season as well. Khari Al-Mateen and Patrick Pascal graduated. Daniel Upson didn’t return for his senior season.

That leaves Hart and four untested freshmen and sophomores to fill two vital positions for Maine. Hart, the largest of the group at 6-foot-3, 210 pounds, is set to start at strong safety. Sophomore Jason Matovu and redshirt freshman Sinmisola Demuren are battling at the free safety spot. Spencer Carey, a sophomore from Fairfield, is listed as Hart’s backup, but he just returned to practice Friday after an offseason knee injury. Mozai Nelson, a redshirt freshman who also is a sprinter on the Black Bears track team, is the fifth player vying for time, his speed being his biggest asset.

They all need to grow up fast if Maine’s defense, which ranked second in the Colonial Athletic Association a year ago, is to reach its potential.

Coach Jack Cosgrove expects that to happen.

“I think we’ll find good players there. When the time comes, we’ll have what I would say is an outstanding secondary that’s going to get better and better as the season goes along,” Cosgrove said.

“We’re not going to sit there and hang our safeties out to dry, either. We’ve got methodology and personnel groups. We’ve got things that we can be aggressive with, too, to be a pain in the offense’s ass.”

It starts with Hart, a steadying influence already for the young group.

Demuren is a more excitable athlete, so impressive in practices last year that he was named the scout team player of the year. In Friday’s morning practice, he made a couple of big plays that impressed Cosgrove, including one on a “Bear drill” when he shed a wide receiver’s block and pinned a running back to the ground.

“I know the plays like the back of my hand. Last year, it was about working harder, now it’s about working smarter,” Demuren said.

“No matter how young you are, you still can take control of a defense, so that’s what I’m trying to be.”

Matovu was a running back at Norwood High School in Massachusetts, walked on at Maine to play wide receiver and was switched to safety last year, although he only played on special teams.

He said he enjoys the physicality of defense now, and that the game has slowed down for him with experience. Matovu also said the safeties are aware that they will be picked on by opposing offenses, and they welcome that.

“We definitely know people are looking at us like the weakness of the defense, but we’re working hard, we’re confident and we’re going to be prepared,” he said.

Carey, who starred at Lawrence High School, has a torn meniscus and a ruptured sac in his knee. He said the meniscus tear appears to have happened two years ago, so the bigger worry is the rupture, which is causing some swelling. The plan is to avoid surgery and play through the injury, which happened over the summer. On Friday, he said he felt no pain in his first practice.

Carey, who also played on special teams last fall, said the safeties will be ready to fill the big void left by Al-Mateen, Burke and Pascal, who combined for 126 tackles last year.

“We’re here to play football and it’s the next guy up in this program and we’re going to be ready for Sept. 5 (the opening game at Boston College),” he said.

“Everyone’s looking at us and saying we don’t have any experience and maybe they’re doubting us. But we’re ready to step up and get to work.” The safeties are being prodded by cornerback Sherrod Baltimore, the lone senior in the secondary. Baltimore has played safety in nickel and dime coverages before, and has been sitting in with the youngsters during nightly film sessions. Cosgrove said moving Baltimore back to safety is a “catastrophe plan” if injuries occur or rookie mistakes become intolerable.

“I really like those guys,” the outspoken Baltimore said of the safeties. “I be down their necks. I don’t let them breathe. If the coach is talking to them, I say, ‘Why is the coach talking to you?’ If they’re supposed to be somewhere, I say, ‘Why were you not there?’

“Because they’re young, you’ve got to hold them accountable. You have to hold them to the highest standards because they’re supposed to be starting for us. I build confidence with them every day. We grind together, we’re going to shine together.”

NOTES: Senior John McCabe of Winslow has been the middle linebacker with the starting unit in practices this week while Christophe Mulumba Tshimanga recovers from an injured Achilles. Mulumba Tshimanga, a junior who has led the team in tackles his first two seasons, said he expects to return to practice by the middle of next week and be able to go 100 percent. He suffered the stress fracture doing offseason running, he said. Nevertheless, McCabe figures to see plenty of action as part of a deep linebacking corps.