“Our pride’s been hurt on defense,” Navy Coach Ken Niumatalolo said. (Jonathan Newton/WASHINGTON POST)

On Sept. 17, the Navy football team came within a whisker of engineering what would have been a monumental upset at then-No. 10 South Carolina thanks in large part to a defense that limited long gains. That’s been the unit’s blueprint since Buddy Green became defensive coordinator 10 years ago, allowing the Midshipmen to thrive despite often facing considerable disadvantages in size and speed.

Lately, though, the defense has been especially susceptible to such plays, including three of at least 30 yards in Saturday’s 63-35 loss to Southern Mississippi, which sent Navy to its first three-game losing streak since 2002. The Midshipmen have permitted five plays of 30 yards or longer over the past two games after giving up two in the first three weeks.

Those substantial gains have contributed to Navy’s defense surrendering 13 touchdowns and 943 yards the last two weeks, starting with a 35-34 overtime loss to Air Force in which quarterback Tim Jefferson completed a 52-yard touchdown pass to Ty MacArthur for the first points of the game.

Failure to stop opponents on third down also has been troublesome. Navy ranks 119th out of 120 Football Bowl Subdivision teams in third-down defense, and over the last two games has allowed opponents to convert 17 of 24 attempts.

So this week, Green and his staff committed to a thorough accounting of personnel, scheme and fundamentals during practice to correct those flaws and ensure a more robust performance against Rutgers this weekend.

“We got totally dominated,” Green said. “We didn’t get off blocks. We couldn’t get any pass rush. We missed too many tackles. We got dominated Saturday. That’s the bottom line. We’ve got to go back to getting more people to the ball, and when we miss tackles or when guys don’t get off blocks, somebody else has got to be there to pick him up..”

In its most recent game, Navy’s defense did not step onto the field until there were 3 minutes 59 seconds left in the first quarter. By then, the Golden Eagles had a 7-0 lead when a blocked field goal led to a 79-yard return for a touchdown on the Midshipmen’s opening series.

After holding Southern Miss to three yards on its first two snaps, the Golden Eagles got a 77-yard pass from quarterback Austin Davis to tight end Ryan Balentine to the 19-yard line. Four plays later, Southern Miss reached the end zone, and the defense continued to unravel from that point.

The Golden Eagles converted four consecutive third downs in the first half before Navy stopped them. Then, on its second possession of the third quarter, Southern Miss amassed six yards on third and four and 35 yards on third and one en route to a touchdown that made it 42-14 with 9:40 left.

“Our pride’s been hurt on defense,” Navy Coach Ken Niumatalolo said. “We’re a very proud defensive team. We’ve been a team that’s prided itself on playing hard-nosed football, and these last two weeks have been uncharacteristic for us. Our deal is we’re going to go back and do what we do and just go to the basics. I’ve great faith that we’ll respond. That wasn’t us. That’s not who we’ve been.”

The confounding part is that the Midshipmen have regressed defensively despite having a full complement of players, at least before this most recent game. Against South Carolina, Navy was without three outside linebackers, including then-starters Jarred Shannon and Mason Graham, yet was able to keep South Carolina, which features several NFL prospects on offense, to 11 points less than its average. Shannon played the past two weeks but did not start, and Graham returned against Southern Miss as a reserve.

Juniors Brye French and Tra’ves Bush have started at outside linebacker for the last three games. Bush began the season as a safety but has distinguished himself at his new position with 32 tackles, second on the team. French, meantime, is fifth on Navy in tackles after missing all but three games last season with a shoulder injury.

“Right now we’re lost, to be honest,” senior defensive end and co-captain Jabaree Tuani said. “I mean we’re stunned. This is devastating for our season right now. Whatever we’ve got to do this week, whatever it may be, we’re going to work on the field, off the field, watch tape in our free time. We’ve got to find a way to go where we need to because right now we’re going backward.”