Due to a plethora of injuries, the Broncos are left with the possibility of missing several starters for Sunday’s game against Oakland. They got some good news Thursday when tight end Vernon Davis returned to practice after clearing the concussion protocol.

Davis took a hard hit from Chargers’ linebacker Melvin Ingram in the second quarter after catching a 9-yard pass from Brock Osweiler last Sunday. The veteran tight end didn’t practice Wednesday, but was in good spirits in the locker room. He is on track to play this Sunday, giving the Broncos a key contributor who’s status was unclear earlier in the week.

“He kind of caught me off guard initially,” Davis said about the hit. “But it wasn’t that bad and I’m ready to go.”

Although Davis was cleared, linebacker Danny Trevathan is still in the concussion protocol and missed his second straight practice Thursday.

If Trevathan is unable to play, linebackers Todd Davis and Corey Nelson would likely split his snaps next to Brandon Marshall.

Quarterback Peyton Manning wasn’t at practice Thursday, but coach Gary Kubiak said that he did a similar throwing routine as Wednesday.

The plan for Manning is to continue that for the rest of the week outside of practice and then re-evaluate the next step for the following week.

Kubiak has already ruled out Manning for Sunday’s game.

Safety T.J. Ward missed his second straight practice Thursday and hasn’t been on the field since suffering an ankle injury Nov. 29 against the Patriots. Ward is unlikely to play Sunday against Oakland. His replacement Sunday, David Bruton, suffered a sprained PCL, MCL and knee bruise during the Broncos’ 17-3 win over the Chargers.

Bruton has been on the field Wednesday and Thursday, but has not participated in any drills. He was on the sidelines with a sleeve on his knee doing some light running on his own. Bruton hasn’t ruled himself out, but it would be a tough jump for him to play.

Reserve safety Omar Bolden also missed his second straight practice with a hamstring injury. Bolden said he was hopeful to play earlier this week.

Denver signed safety Shiloh Keo to help with depth at the safety position.

“This is the longest list I’ve ever had,” Kubiak said of the Broncos’ injury report.

Running backs C.J. Anderson (ankle) and Ronnie Hillman (foot) missed their second straight practice. Juwan Thompson could be in store for a big role Sunday if either of the top two backs can’t play or are limited.

Kubiak said he expected both Anderson and Hillman to be full participants Friday at practice. Their progress will determine their status for Sunday.

Outside linebacker DeMarcus Ware continues to make “really good progress” and Kubiak expects him on the field for a limited number of plays Sunday if he doesn’t have any setbacks.

“I don’t really think about how many snaps,” Ware said. “I think about how many times I’ll get to the quarterback.”

Outside linebacker Shane Ray was sent home with an illness.

Cameron Wolfe: 303-954-1891, cwolfe@denverpost.com or @CameronWolfe