Virginia's already thin secondary will face an even greater test of its depth on Friday night.

Free safety Ethan Minter was one of 20 Cavaliers declared out for the Cavaliers' crucial Atlantic Coast Conference home matchup against Duke. The junior suffered an undisclosed injury in last Saturday's 23-13 loss at SMU.

His absence further depletes a secondary that already lost starting cornerback Omillio Agard to a season-ending ACL tear against Florida State three weeks ago. Backup safety Corey Costner was also declared out for a second straight week due to a hamstring injury.

Additionally, starting strong safety Brandyn Hillman -- arguably Virginia's best defensive player in the first half of the season -- was listed as questionable with an ankle injury he suffered against Delaware two weeks ago. He missed the SMU game.

Who steps up?

Minter's starting spot likely will be filled by Virginia Tech transfer Christian Ellis or junior Keke Adams. Sophomore Montino Williams will make his third straight start (and fourth of the season) if Hillman can't play.

"He's an extremely hard worker," coach Tony Elliott said of Williams on Tuesday. "Man, he's about all the right things, both on and off the field. He's probably got one of the highest GPAs on the back end of all those guys. So, he's a guy that's fully committed, and he's been like that since the day he showed up."

Wide receiver Rico Flores Jr., was also among the players ruled out for Duke. He has made just one start (against Syracuse) since transferring in from UCLA due to hamstring and knee injuries, and his return this season remains in doubt.

Receiver Kam Courtney is listed as questionable. He leads the Cavaliers with 18 receptions this season.

While the secondary injuries are a concern, Duke's offense relies largely on its running game. Sophomore Nate Sheppard leads the ACC with 820 rushing yards and eight touchdowns on the season.

Three players listed as starters on Duke's depth chart have been listed as out: center Matt Craycraft, nose tackle David Anderson and safety Andrew Pelliccotta. Craycraft is one of Sheppard's most effective blockers, while Anderson and Pelliccotta are key cogs in a defense that ranks second in the ACC, allowing just 292.7 total yards per game.

Duke (4-2, 1-2 ACC) has lost two straight games entering Friday night's nationally televised game (7 p.m., ESPN). Can they get an important win and get closer to bowl eligibility?