ENGLEWOOD, Colo. (AP) C.J. Anderson might be going from breakout to heartbreak.
The Denver Broncos were bracing for bad news on their starting running back, who they sent for a second opinion on his ailing right knee Wednesday.
Anderson hurt it on an 11-yard run on the final play of the first quarter Monday night against Houston but returned to the game and ran 14 more times for 84 yards to spark Denver's 27-9 win.
His 107-yard performance on 16 carries marked his first career 100-yard game before Halloween. Combined with rookie Devontae Booker's big night, the Broncos (5-2) finally snapped out of an offensive funk by rushing for nearly 190 yards.
They left the stadium feeling really good about their new 1-2 punch in the backfield, but Anderson showed up sore Tuesday. They'll know Thursday how much time he'll miss.
''We're just really trying to evaluate it more than anything,'' coach Gary Kubiak said. ''He played with it. He did it early in the game. He played through it, he played really well. Actually, he was our offensive MVP. He came in really sore the day after. So, we're trying to evaluate where he's at right now.''
With Anderson down, the Broncos would start Booker on Sunday against San Diego and Kapri Bibbs would back him up.
''It's kind of up to Book, how much can he handle, what kind of load can he handle? But I think he played really well the other night,'' Kubiak said. ''Kapri's been chomping. So, we'll see where C.J.'s at.''
Anderson's injury could thwart the momentum they found in their ground game, which opened up passing lanes for their wide receivers by game's end as Houston was forced to bring a safety closer to the line of scrimmage to help against the run.
Booker, who ran for 83 yards and his first career TD on 17 carries against the Texans, said he's ready for a bigger role if Anderson's sidelined.
Quarterback Trevor Siemian said he's comfortable with Booker, too.
''Book is a stud and he's been running really well for us the last couple of weeks,'' Siemian said. ''Hopefully we get C.J. back again because you would like to have two that are playing really well. But I have a lot of confidence in Book, Kapri and whoever else is back there.''
Also Wednesday, tight end A.J. Derby, acquired from New England for a 2017 fifth-round draft pick, practiced with his new teammates for the first time.
''We think he has a chance to help us really quickly,'' Kubiak said.
Kubiak acknowledged a fifth-rounder was a steep price to pay for a backup this deep into a season, but said injuries to Virgil Green and Jeff Heuerman have stymied the Broncos and ''we think this kid's got a bright future.'' He added, ''I'd be very comfortable'' playing him Sunday against the Chargers.
Playing behind Rob Gronkowski and Martellus Bennett, Derby played just 36 snaps. But his preseason production - 15 receptions for 189 yards and a TD - is roughly what the Broncos' tight ends have managed this season.
''Obviously they have a good room back in New England. It was fun to learn from them,'' Derby said. ''... We have a good room here, as well. I'm just excited to compete with those guys.''
Notes: C Matt Paradis (hip), MLB Brandon Marshall (left hamstring) and NT Sylvester Williams (ankle) also missed practice as did backup C James Ferentz (non-injury). ... Marshall said he hasn't had a pulled hamstring this bad since 2008.
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