ENGLEWOOD, Colo. (AP) - The Denver Broncos were counting on Ty Warren to anchor their run defense after sitting out the previous two seasons with injuries.
That plan lasted all of five snaps before the veteran defensive tackle re-tore his right triceps in the opener and went on I.R., ending his season and likely his career.
Filling the void for the Broncos (1-1) are a beefed-up Kevin Vickerson, 11th-year pro Justin Bannan and Colorado native Mitch Unrein, a second-year pro who went undrafted out of the University of Wyoming.
"Tremendous," is how coach John Fox described their play, quickly adding the admonition that "we're two tests into a 16-test exam, but so far, so good."
The Broncos held the run-oriented Pittsburgh Steelers to 2.9 yards a carry in the opener and the Atlanta Falcons to 2.4 yards a carry.
They thwarted Steelers running back Isaac Redman (20 yards on 11 carries) and Falcons running back Michael Turner, who gained just 27 yards on 16 carries before a 15-yard scamper on his final carry.
New defensive coordinator Jack Del Rio was more interested in talking about the Houston Texans (2-0), who visit Denver on Sunday.
"Two games is too small of a sample," Del Rio said. "We've done a good job of starting the year, but this week coming up is a huge test and you'll learn more about us in that phase and us in general as we go through the year."
Texans running back Arian Foster has 189 yards and three TDs so far.
"They're one of the top rushing teams in the league, and we pride ourselves in stopping the run, so it's a good test for both of us," Vickerson said.
Foster was equally impressed with the Broncos.
"From what I've seen so far, they're one of the best defenses in the NFL," Foster said. "They're so quick. They're fast. They ran to the ball and they're just ... honestly, they're exciting to watch."
Vickerson is a load in the middle after adding 40 pounds to his 6-foot-5 frame in the offseason once Del Rio arrived and told him he needed to put on weight.
Vickerson now weighs 330 pounds, 30 more than Warren.
"Yeah, because a year ago with the lockout and everything, he came back and looked like a wide receiver," Fox quipped. "That's a little extreme, but he had lost a lot of weight. So, we just had to get him back ready to play what we're asking him to play and he's doing a great job with it."
Vickerson said the weight gain is paying off and so it's not too early to take pride in the job the Broncos' run-stuffers are doing.
"The first two games, that's what we put on tape. The preseason, that's what we put on tape, that we're going to play good against the run, that we're going to come out and establish our run defense," he said. "I don't think it's a misstatement, I mean, teams got to build something, right? That's how we started, that's how we're going to go."
The Broncos spent the week correcting lots of things that didn't go right in their 27-21 loss at Atlanta, when Peyton Manning threw three interceptions, including two wobbly ones, in the first eight minutes before settling in and nearly pulling off the comeback from a 20-point deficit.
Manning mentioned earlier in the week he was miffed at the thought he looked dejected on the sideline at the end of the game, insisting, "I think it was more of a determined look." As for lack of zip on some of his passes, he shrugged off questions about his arm strength, saying if it's not what it used to be, "It is what it is."
On Thursday, Manning flashed a sense of humor. During a passing drill near the end zone where reporters gathered to watch the start of practice, he admonished everyone to pay attention.
"Hey, those wobblers still hurt (if) they hit you in the head," he cracked.
Notes: LB Von Miller, who was limited a day earlier with a sore hip, was a full participant in practice Thursday. ... CB Chris Harris (right ankle) practiced for the first time since spraining his right ankle in the opener. ... CB Tracy Porter (neck) was added to the injury report but participated in all the workout.
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