ENGLEWOOD, Colo. — Nate Jackson was just about to address the Denver Broncos' spate of injuries when a television reporter accidentally bashed him in the mouth with his heavy microphone.

"Yeah, that would have been a horrible way to get put on injured reserve," the backup tight end said.

The Broncos (4-1) can ill afford any more ailments.

Coach Mike Shanahan announced today that the AFC's best offense will be without two of its key components against Jacksonville on Sunday: tailback Selvin Young and tight end Tony Scheffler.

Both strained groins in Denver's rain-soaked win over Tampa Bay last weekend.

Head trainer Steve Antonopulos "thinks both will be ready for the Monday night game" at New England on Oct. 20, Shanahan added. "So, that's a good sign."

Receiver/returner Eddie Royal sat out Wednesday's workouts with a bruised bone on his sprained left ankle, and defensive end Ebenezer Ekuban (groin) also missed practice, but Shanahan said both are expected to be available against the Jaguars (2-3).

When Royal got hurt, Glenn Martinez, signed just last week, stepped in and made big plays on offense and special teams, and if Royal's not ready, he'll get plenty more chances this weekend.

The Broncos had been relatively healthy so far.

Darrell Jackson (calf), whose lone reception was a 48-yard touchdown in the opener a few days before he got hurt at practice, hopes to return to action Sunday.

The only other significant loss was nose tackle Dewayne Robertson (knee), whose presence was sorely missed in a loss at Kansas City when Larry Johnson ran for 198 yards.

With Young and Scheffler out, the Broncos will almost certainly rely more on running back Michael Pittman and Nate Jackson.

"We still got some guys," quarterback Jay Cutler said. "We've got a bye week coming up in the next couple of weeks and hopefully he can get them healthy and have them the rest of the year. We will be fine, though, we'll will get through this. It is part of the NFL."

The Broncos are deep at receiver, running back and tight end, and that depth is about to be tested.

"It's hard to go 16 games in this business without people going down," receiver Brandon Stokley said. "On the good teams, other guys ... make plays, and that's what we're expecting."

Pittman has served as the Broncos' short-yardage specialist and has been angling for more carries. Young's injury should allow him to at least split snaps with tailback Andre Hall.

"I'm looking forward to playing and if my number's called a lot more, I'll definitely appreciate that and I'll do my thing," Pittman said.

Nate Jackson was starting ahead of Scheffler alongside Daniel Graham in two tight-end sets just last month, and he'll get more work until Scheffler gets healthy.

"Injuries are always unfortunate but guys have always got to be able to jump in and make plays when they're called upon," Nate Jackson said. "And my preparation's not going to change at all. Hopefully, the offense won't change at all, either."

He added that everybody's playing with some aches and pains by now, "and my tooth hurts, thanks to you," he told the reporter who haphazardly struck him in the face.

With Scheffler down, the Broncos signed Chad Mustard, a fifth-year tight end from North Dakota who has been waived nine times in his NFL career and has had five separate stints with the Broncos.

"I went to double digits, this is the 10th time" to sign a contract, said Mustard, who missed all of training camp with a pulled hamstring.

Mustard, who plans on teaching high school math whenever the Broncos quit calling, never takes the ups and downs of being the 53rd man on the roster personally.

"Football's been good to me, my wife and my family. So, I'm just going to enjoy it and hopefully I can squeeze a few more games out of this old body," said Mustard, who celebrated his 31st birthday Wednesday.