ENGLEWOOD, Colo. -- Since the start of training camp and through Derek Wolfe's four-game suspension to open the season, the Denver Broncos have consistently lauded their depth in the defensive line.

However, that depth will be tested this week against the Chicago Bears since the Broncos have had two defensive linemen -- Antonio Smith (hip) and Vance Walker (shoulder) -- held out of practice for the last two days as both remain question marks to play Sunday.

“I kind of expected them both back (Thursday)," Broncos coach Gary Kubiak said. “ ... We’ll see. I thought maybe Antonio would practice a little bit (Thursday), I wasn’t surprised Walker did not practice."

It means that two of the five defensive linemen who have played at least 230 snaps on defense this season for the Broncos have yet to practice this week. The Broncos did practice indoors, on a turf field, Wednesday and Thursday, and Kubiak acknowledged that some decisions about practice participation were made with that in mind.

Toss in the fact that outside linebacker DeMarcus Ware (back) also missed this past Sunday’s game against the Kansas City Chiefs and will miss this Sunday’s game against the Bears, and the Broncos will likely have to adjust their rotations in the defensive front seven.

Kubiak said he hopes either Smith or Walker will “be there for us on game day." Rookie nose tackle Darius Kilgo, who has been a game-day inactive for the last four games, would likely be in the rotation against the Bears if either Smith or Walker doesn’t play.

The Bears, with former Broncos offensive coordinator Adam Gase calling the plays, have protected quarterback Jay Cutler well. Cutler, who has missed one start this season, has been sacked just 12 times and thrown just five interceptions.

No team has sacked Cutler more than twice in any game this season and he is on pace for a career low in interceptions for any season he started at least 10 games.

“Cutler is playing as well as I have seen him play," said Broncos defensive coordinator Wade Phillips. “He's obviously been a real talent for a long time. Any time that you play a quarterback that can win the game himself, those are the really good quarterbacks. He's always been talented. He's always had a chance -- if you stopped everything else, he still might beat you. He's always been that kind of guy.’’

“Gase has him going in the right direction," said Broncos cornerback Chris Harris Jr. “The way their offense is running is almost similar to what we've done in the past. That's what makes it easier for us as defensive guys or who's been practicing against them for a while. I think Cutler is playing a lot smarter with the ball. I think that's working for them."