ENGLEWOOD, Colo. -- Put it on the pile of things that haven't gone the way the Denver Broncos have wanted them to go. The team now has what coach Vance Joseph called "a flu bug" racing through the building.

Broncos defensive end Shelby Harris was held out of Wednesday's practice with an illness and linebacker Shane Ray was limited in practice with an illness as well. In all, Joseph said multiple players have been affected in recent days.

"It's a flu bug, so hopefully guys take care of themselves so we can get a handle on that," Joseph said. "It's about four, five guys who are sick right now."

With Harris' absence Wednesday, the Broncos defensive line has been particularly hard hit. Nose tackle Domata Peko missed two days of practices last week with an illness as well.

With Derek Wolfe's neck injury still being evaluated and Peko's knee injury suffered during the loss to the Oakland Raiders, the Broncos had rookie DeMarcus Walker practice with the defensive linemen Wednesday. Walker has spent much of the season at outside linebacker.

"We only had three guys today healthy enough to practice -- he's always going to be a swing guy for us," Joseph said. On Wolfe's injury , Joseph added: "He is being evaluated and when you're talking about a neck, head injury, you want to be smart with those guys. Obviously his overall health is more important than the next five games. We want to make sure he's ready to play before he gets back on the field. And it's a neck injury and that can be scary without knowing everything about it."

Quarterback Trevor Siemian, who will make his eighth start of the season Sunday against the Dolphins, is one of the players battling the illness.

"A couple of us got it, we'll be alright," Siemian said.