According to Mike Klis of 9News in Denver, Anderson will have the surgery because of a torn meniscus in his right knee.
Ian Rapoport of NFL Network noted it will be an arthroscopic procedure, likely forcing Anderson to the injured reserve list.
Kevin Patra of NFL.com noted Anderson initially wrote "false" on his Twitter page when reports came out he could miss the season. However, the running back deleted the post:
Josh Alper of Pro Football Talk clarified Anderson is "not automatically" done for the 2016 season because Denver can wait six weeks to designate him as a player who is eligible to return from IR. Still, Anderson wouldn't be eligible to be on the active roster until eight weeks from now, which means he will be out until Week 16 at the earliest.
Anderson has 437 rushing yards, 128 receiving yards and five total touchdowns through seven games this season.
The timing is particularly cruel for the 25-year-old considering he is fresh off a season-high 107 yards on the ground in Denver's Week 7 victory over the Houston Texans. He was also a force in the Broncos' championship run last year with 720 rushing yards and five touchdowns in the regular season and a touchdown against the Carolina Panthers in the Super Bowl win.
Look for the Broncos to turn to rookie Devontae Booker as the lead back moving forward.
The Utah product saw double-digit carries for the first time against Houston (17) and took full advantage for 83 yards and a score. He also flashed his potential at Utah with a combined 2,773 rushing yards in 2014 and 2015.
Booker is averaging a solid 4.8 yards per carry this year and will have the opportunity to run behind the sixth-best run-blocking offensive line in the league by Football Outsiders' metrics.