Sanders missed Wednesday's work with an ankle injury, but had a full practice workload Thursday. Harris, who was sidelined Wednesday because of an illness, saw limited work Thursday.
Guard Ron Leary (back), quarterback Paxton Lynch (ankle), outside linebacker Shane Ray (wrist/illness), defensive end Derek Wolfe (neck) and nose tackle Domata Peko Sr. (knee) did not practice.
If Leary cannot play, second-year lineman Connor McGovern could be part of the plan to fill in for him. McGovern filled in for center Matt Paradis throughout the offseason and preseason, but he has never started in the regular season.
"We've got some guys that can step in; he's one of them," Head Coach Vance Joseph said.
Wolfe is still receiving tests on his neck, Joseph said, as the Broncos are "being really careful" with his injury.
"When it's the neck, it's serious," Joseph said. "It's his life. So we want to be smart there with his injury."