CHARLOTTE – Veteran defensive end Brian Burns admitted it doesn't feel quite the same on the field, when so many critical pieces of the Panthers defense aren't available.

But he also said those absences shouldn't be too much for the unit to overcome.

The Panthers went into Sunday's 37-15 loss to the 49ers without three of their four leading tacklers – linebacker Frankie Luvu (shoulder) and both starting safeties, Jeremy Chinn (hamstring) and Xavier Woods (hamstring) – and lost standout corner Jaycee Horn to a hip injury late in the third quarter.

"It's different," Burns said. "Frankie brings a lot of energy, a lot of juice; he makes a lot of splash plays. X is one of our main communicators in the backend. Chinn's the enforcer. So it does make a difference, but we've got guys that can step up."

Chinn's absence was known. He left early in the Week 4 loss to Arizona with a hamstring injury that placed him on injured reserve this week. But when it came to Luvu and Woods, there was a general feeling of optimism about their availability.

Woods didn't practice this week, and Luvu was limited on Friday, but head coach Matt Rhule said he woke up Sunday morning thinking they would play. But Luvu and Woods were declared inactive after they worked out on the field before the game.

"It's a long season; we don't want guys hurting themselves," Rhule said. "Laviska (Shenault) went last week and got banged up. The decision was made that (Luvu and Woods) couldn't go."

It's challenging to replicate the kind of production Luvu was getting before he was ruled inactive. He was the Panthers' leading tackler, and had also forced a fumble and brought an interception back for a touchdown — triggering two straight weeks of defensive touchdowns.

In his sixth year, Woods emerged as a key voice helping the Panthers' defense adjust on the field. Chinn's a team captain in just his third season, after becoming only the third player in Carolina history to total at least 100 tackles in each of his first two seasons.

Seven-year linebacker Cory Littleton filled in for Luvu, while safety-nickel hybrid Myles Hartsfield and former starting safety Juston Burris, signed to the active roster from the practice squad this week, started at the two open spots in the secondary.

Rhule said while they missed Woods, his early evaluation of Burris' performance on Sunday was positive. Burris finished the game with eight total tackles. That trailed only linebacker Damien Wilson, who had nine tackles, a sack, three tackles for loss, and a forced fumble.

But without its stalwarts at safety and an essential energizer at linebacker, Carolina's defense allowed a season-high 37 points to Jimmy Garoppolo and the 49ers' offense. The 22-point margin of defeat was the Panthers' largest of the season.

Rhule credited the 49ers' offense in the first half with making "great plays," going over the top of defenders in the secondary to make contested catches. Garoppolo totaled 253 yards and two touchdowns on 18-of-30 passing, and four different 49ers (Brandon Aiyuk, George Kittle, Jauan Jennings, and Tevin Coleman) had 44 or more receiving yards.

There were some standout plays — such as Wilson's forced fumble that Yetur Gross-Matos recovered his blocked field goal attempt. But those efforts weren't enough to keep the game particularly close.

Burns reiterated a difference in personnel isn't an excuse for how the game went. The 49ers' offense uncovered gaps in the defense, and they converted on 7-of-12 attempts on third down.

"At the end of the day, we've got a lot of guys," Burns said. "(San Francisco) just found holes in the zones and defense, and they executed. They did pretty well on third down; that was a problem."

Cornerback Donte Jackson agreed with Burns' assessment, placing blame on the defense's execution.

"Just got to execute," Jackson said. "We did a lot of things wrong on defense today. (We've) got to tackle better, starting with myself, got to get off the field on third down, and just execute."

Amid a 1-4 start to the season and a swath of injuries on the defensive side of the ball, Burns said he and other leaders on the defense, including linebacker Shaq Thompson, have the responsibility of keeping teammates motivated.

"I put it on us because, at the end of the day, we're the glue that holds everybody together," Burns said. "I've got to keep the team together. That's my job, along with doing my job on the field. And I take a lot of pride in it."