**

ENGLEWOOD, Colo. -- **Takeaways from an injury-marred practice at the UCHealth Training Center on Monday ...

1. WALKER SUFFERS TORN ACL

The Broncos ended practice hoping for the best for the starting defensive end after he was carted off the field and could not put weight on his right leg, but a Monday afternoon MRI examination revealed the Broncos' worst fears: a torn anterior cruciate ligament.

His absence will be felt. The 29-year-old veteran was enjoying his best training camp to date, having established himself as the leader in the race to replace Malik Jackson.

"He came in here, and since he reported back in the offseason, man, he had a different approach to himself, because he had big shoes to fill," nose tackle Sylvester Williams said.

"It's going to be a big loss for us ... I know he's a tough guy and he'll fight through whatever it is."

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2. WHO MUST STEP UP FOR WALKER?**

The immediate answer is Jared Crick, who played in Houston for Defensive Coordinator Wade Phillips and Defensive Line Coach Bill Kollar. He developed into a first-teamer the last two years, and started 31 regular-season games the last two seasons, notching 5.5 sacks and 104 total tackles in that span.

"Hopefully [Walker] is going to be all right," Crick said. "My mindset has to stay the same, just come out and try to improve on my game every single day. Wherever guys are on the depth chart, they have to keep the same mindset to get through camp. Come week one, wherever guys are at, whatever their roles are, we'll go from there."

Adam Gotsis could also factor into the mix; he had a pressure of Chicago QB Brian Hoyer that led to a Vontarrius Dora sack last Thursday and is receiving a full practice workload after recovering from a torn ACL.

"I think it took a while coming off his knee, so you see him improving his physical condition at practice," Head Coach Gary Kubiak said. "He's taking what Bill teaches. He's still has a long way to go as a young player, but obviously we're counting on him big time."

Veteran Billy Winn, who was signed during training camp, could also be a rotational factor, and nose tackles Sylvester Williams, Kyle Peko and Darius Kilgo could see a greater role in two-down lineman sub packages if necessary.

Even before Walker went down, injuries had been a story for the defensive line. Phil Taylor was placed on injured reserve and eventually waived because of a knee injury, and Kenny Anunike was waived after trying to rehabilitate from a knee injury suffered last year.

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3. SIEMIAN RUNNING THE SHOW**

Trevor Siemian received the bulk of the first-team repetitions Monday, and with his work under pressure and in the two-minute period, looked as comfortable as he has at any point to date during training camp.

Siemian's first and last connections during team periods Monday were on deep shots. He found Emmanuel Sanders up the right sideline past Aqib Talib to open his day, followed that with a long play-action connection to Jordan Norwood two plays later in which he fired a pass across his body and under a rush, showing the same kind of poise under a rush that he demonstrated when he escaped the pocket for a 22-yard pass to Jordan Taylor last Thursday.

Siemian's deep strike to Demaryius Thomas in the two-minute drill period set up a field goal and capped his day.

4. DARRION WEEMS STILL GETTING A CHANCE

The tackle-turned-guard worked extensively on the first team at right guard on Monday, even though co-No. 1 right guard Michael Schofield was available for first-unit work with Russell Okung and Donald Stephenson working on the first unit at left and right tackle, respectively.

Weems' background as a tackle puts him in a potentially interesting spot. Even if he doesn't earn a first-team position by the end of the preseason, every snap he gets at guard makes him more versatile, and gives him the potential to serve as a fill-in at three offensive-line positions -- both tackle spots and right guard. That versatility nearly matches Schofield's capability to play every position but center.

With Ty Sambrailo still "week-to-week" because of his right elbow injury, Weems is maximizing his opportunity.

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5. HILLMAN FIGHTING FOR HIS SPOT**

Most of Ronnie Hillman's work Monday came with the third team, as he rotated behind starter C.J. Anderson and co-No. 2 running back Devontae Booker. "He's in a hell of a battle with Kapri [Bibbs] and Book right now," Kubiak said. "There's no way around that; I'm just being honest with you."

Hillman rotated in for some work as a blocker on kickoff returns, something he will need to do if he is going to stick on the 53-man roster after the preseason.

"Special teams are going to be really important," Kubiak said. "Ronnie's going to play a lot this week and play some special teams, so it's a very competitive situation."

6. TIME TO SEE ANOTHER FOE

The second- and third-teamers got plenty of work against other opposition on Thursday, but the first team did not. Some only played the first quarter; others were held out of the 22-0 win at Chicago altogether.

Two of those top-line players, Chris Harris Jr. and Emmanuel Sanders, saw their one-on-one duel in a team-period snap mushroom into a full-fledged shoving match that saw defensive backs T.J. Ward, Bradley Roby and Darian Stewart rush over to the tussle. Harris was called for pass interference, the contact continued after the play, and while neither Harris nor Sanders were dismissed from practice, they both sat out when the first team was at work during the subsequent move-the-ball period.

"We have to keep our composure," Kubiak said. "Guys are going to get upset and battle each other, but there are some things that they won't let you do on the field, so we can't do those at practice either. They were just competing."

The first-teamers could use a greater chance to go against other foes. Beginning Wednesday when the 49ers arrive for the first of two joint practices, they will receive it.

"We're tired of practicing against each other," Kubiak said.