ENGLEWOOD, Colo. --The Broncos concluded their week of practice in advance of their trip to Tennessee not knowing who would be under center when they line up for their first snap at Nissan Stadium on Sunday.
1. WAIT-AND-SEE AT QB
First-team quarterback Trevor Siemian practiced all three days this week, and on Friday showed no lingering aftereffects from splitting the Thursday repetitions with Paxton Lynch. He appeared to have no trouble putting his weight on his left foot as he threw early in Friday's practice.
But the biggest test will come Saturday, when the Broncos see how Siemian feels following his work Friday.
"There are certain ways they are trying to protect it and tape it," Head Coach Gary Kubiak said. "Bottom line, can you do what you need to do to play? He's shown the last couple of days that he's been doing that. We'll just see how he feels."
If the Broncos need Lynch to start again, he hopes to display more accuracy than he did in a 12-for-24 performance in which he missed some open target short and to the outside and deep off play-action.
"I think just going back on the film, there was a couple of times I had a shot to give those guys a chance on the outside to make a play on the ball, but I didn't put it where I needed to," Lynch said. "I think that will come whenever I get more reps with them and we have better timing."
- COPING WITHOUT BRANDON MARSHALL**
With Marshall ruled out for Sunday because of a hamstring injury, Corey Nelson is expected to start in his place and relay the play calls, wearing the helmet that is equipped with a radio receiver.
Nelson's playing time has increased the last few weeks as Defensive Coordinator Wade Phillips has made more use of him in sub packages, but was pressed into every-down service last week when Marshall left because of the injury.
"When we started playing him in the sub packages quite a bit, he played well against the run in sub, which was pleasing," Defensive Coordinator Wade Phillips said. "He's been a good cover guy. He's such a good athlete. With him playing more in the base defense, he's a good tackler and can really run. He's got a lot of ability."
Nelson's experience is also an asset; the third-year veteran has played in playoff -- and playoff-type -- games like the one the Broncos will face Sunday.
"Every week from here on out has been a playoff game and it's going to continue to be a playoff game. We have to treat it as that and play it as it is," Nelson said. 'This is a game that we must win."
- DEALING WITH DELANIE WALKER**
Tennessee's Pro Bowl tight end has become Mariota's most valuable target, and given the Broncos' troubles with covering some tight ends this season, he has the attention of Denver's defense.
"He's a real threat," Phillips said. "Most of the time the tight end isn't the No. 1 target. Most of the time a wide receiver is the No. 1 target. He's their No. 1 target on their team and you can see why."
Walker has 12 receptions of at least 20 yards. Only one tight end, Kansas City's Travis Kelce, has more. He has 26.1 percent of the Titans' passes of 20 or more yards; only Kelce and Carolina's Greg Olsen have higher percentages.
He's also a complete tight end, having honed his blocking skills during his years with the 49ers, when Vernon Davis was his complement, handling the bulk of the pass-catching work.
"He's fast, quick, strong and he can block," said Broncos OLB Von Miller. "When he was with the 49ers, he was probably the fastest tight end that they had -- and we all know what type of speed Vernon Davis has."
- WHO GETS THE MOST CARRIES? IT DEPENDS WHO HAS THE HOT HAND**
Justin Forsett got up to speed this week and will play Sunday, Kubiak said.
"I will play him," Kubiak said. "Will it be half the time, will it be less than Book, I don't know, we'll see how the game goes. But I like [his work in] practice. He knows exactly what he's doing. I think he's brought some nice juice to our football team, our offense."
Forsett's knowledge of the scheme from two previous seasons under Kubiak in Houston and Baltimore helped him get up to speed to the point where he can get some extended repetitions Sunday if he's playing well, not just occasional relief in place of Devontae Booker.
"I think so," Kubiak said when asked whether he would play the hot hand Sunday. "I think that's the way [Running Backs Coach] Eric [Studesville] goes about it. We always go in with a plan how we're trying to play them, and then we see how things go."
Kubiak said Forsett brought "a little bit of juice" to the locker room this week, and that he spoke to the entire team about his appreciation of the opportunity that emerged in the wake of Kapri Bibbs' high ankle sprain and C.J. Anderson's torn meniscus suffered on Oct. 24.
"[Forsett] is a very sharp kid, a very positive guy. He's got his head on straight as far as football," Kubiak said.
- AGE IS JUST A NUMBER FOR DEFENSIVE COORDINATORS**
Phillips is 69. Titans defensive coordinator Dick LeBeau is 79. Both broke into the NFL coaching ranks in the 1970s, before any of their current players were born. But both continue to get results, with LeBeau guiding the Titans to across-the-board improvement that starts with the disruptive interior presences of Jurrell Casey and Karl Klug.
"He's in the Hall of Fame as a player, but really he should be in the Hall of Fame as a coach, too," Phillips said of LeBeau. "He's tremendous. If they ever put assistant coaches in the Hall of Fame, he would be one that I would put in for sure."
Both are tactical masterminds, but neither would be able to get their results without their continued ability to relate to playoffs more than half a lifetime younger.
Phillips, in particular, has built a special relationship with this defense.
"You would think with a guy that has his age that he wouldn't be able to relate to the young guys and that's who he flocks to," said outside linebacker Von Miller. "When he first got here, me and Wade talked and joked. I wasn't expecting that. I've had older coaches before and it was 'Yes, sir' and 'No, sir' and you get your job done. [There was not] really a sense of humor in all of that stuff, but Coach Phillips has been doing it a long time and you can really tell. He is really balanced."
Can Taylor Lewan handle Von Miller? Will Derek Wolfe get to Marcus Mariota? Those are just two of the matchups that could decide Sunday's game. (Photos by AP)