Seemingly in defiance, Danny Trevathan carried, rather than used, his second set of crutches in two months as he hobbled through the locker room. That limp was considerably more pronounced Monday than it was after the game against the New York Jets in which he barely played Sunday.

Broken bones are funny that way.

Danny, Danny, Danny, someone said from one side of the locker room. Trevathan ducked his head and shook it in disbelief.

The Broncos’ starting weakside linebacker will miss the next three to six games after suffering another fracture in his left kneecap area. Trevathan will not need surgery.

Trevathan would be a candidate for the injured reserve list with a designation to return in eight weeks, although as of Monday the team was not ready to make such a declaration.

“I do feel for him,” said Broncos rookie linebacker Corey Nelson, who played 58 percent of the defensive snaps against the Jets in relief of the injured Trevathan. “But I also know that if Danny was in my shoes, he would want me to perform the best that I can, or anyone, for that matter.”

Given the Broncos’ next three opponents are the formidable San Francisco 49ers, San Diego Chargers and New England Patriots, Trevathan’s second injury stint might be more difficult to overcome than his first. He missed the season’s first three games because of a fracture in the leg bone just below the left kneecap, an injury suffered during training camp. He was on crutches for nearly three weeks, obediently keeping weight off his knee.

Trevathan returned to play a full game against Arizona last week, then suffered another fracture near the left kneecap on the second defensive play Sunday against the Jets.

Broncos coach John Fox said this fracture was “nothing even remotely the same as his last injury.”

Then again, it’s close enough to the same area in such a short time since the first injury to make one wonder if he has a functional issue with the knee. The Broncos are hoping this break will mend a little more quickly than the previous one.

On a wide receiver screen to former teammate Eric Decker, Trevathan got caught going against two Jets blockers who were moving with their full weight forward on a dead run. Trevathan got trampled, and his left kneecap dislocated. As the kneecap popped back into place, a bone at the top of the kneecap fractured.

“It’s a tough break for Danny — just got back and second play of the game,” said Brandon Marshall, who again will replace Trevathan at starting weakside linebacker. “It’s crazy that it happened to him twice like that, but at the same time, it’s the NFL.”

Yes, devastating injuries are a part of the NFL. Marshall replaced Trevathan during the Broncos’ first three games. As before, Marshall will again get the speaker from Trevathan’s helmet and call the defensive plays.

“It was an easier transition this time,” Marshall said. “The (Indianapolis) Colts game, I am not going to lie, I was a little nervous. I think at this point, the game has slowed down for me.”

Nelson got extra playing time against the Jets, but against the more physical 49ers, don’t be surprised if the Denver defense employs packages heavier with middle linebacker Nate Irving.

When healthy, Trevathan is a maniacal tackler whose range is sideline to sideline. He led the team with 124 tackles last season. The team’s second-leading tackler, Wesley Woodyard, had 83.

This year Trevathan has only seven tackles, all coming in Game 4 against Arizona.

Mike Klis: mklis@denverpost.com or twitter.com/mikeklis