He is out indefinitely.
Whether Anderson has a full or partial tear in the meniscus will be determined during the arthroscopic procedure, and a repair could be made. A full tear would almost surely end his season, and a partial tear could mean a four- or five-week absence.
If the Broncos elect to put Anderson on injured reserve and want to bring him back this season, he has to be out for a minimum of six weeks before he can return to practice and has to be out for a minimum of eight weeks before he can play in a game.
"So that we can further evaluate what's going on and go from there," Kubiak said of the surgery. "Hopefully [Thursday night] we have some idea of what's happening and see where we're at when we wake up [Friday] ... Lot of people involved."
Anderson posted a tweet Thursday afternoon to thank the team and fans for their support and noted that his status for the season will not be known until after his surgery.
Anderson suffered the injury during an 11-yard run on the last play of the first quarter of the Broncos' 27-9 victory over the Houston Texans Monday night. As he closed in on Texans cornerback A.J. Bouye, Anderson tried to make a cut just before contact, planted his right foot and his knee buckled slightly as he then was tackled.
Anderson sat on the field for several moments after the play, talking to the Broncos' trainers, and at one point grabbed his lower right leg. Anderson returned to the game in the second quarter, with a 3-yard run eight plays later.
He finished the game with 107 yards on 16 carries, his first career 100-yard rushing game before Halloween.
"He played in the game, he played through it,'' Kubiak said. "There's obviously something they need to go repair, so let's just see to what degree that is.''
Kubiak said he spoke to Anderson by phone Thursday morning before the team meeting.
"He's in good spirits, he's out there with his family,'' Kubiak said. "I think he understands what we have to go do and just keep our fingers crossed on the other end.''
Rookie Devontae Booker, who had 83 yards rushing against the Texans on Monday night, will start Sunday's game against the San Diego Chargers at running back. Kapri Bibbs will be the No. 2 running back, and the Broncos have running back Juwan Thompson, who has been on the roster the previous two seasons, on the practice squad.
The Broncos matched an $18 million offer sheet to Anderson from the Miami Dolphinsthis offseason. Anderson has 437 yards rushing this season to go with four rushing touchdowns.
"[Booker] is a stud,'' Broncos quarterback Trevor Siemiansaid. "And he's been running really well for us the last couple weeks, so hopefully we get C.J. back again, because you like to have two.''