Fangio's remark comes five days after the first-year head coach said it was not "vitally important" for Lock to play this season.
The change of heart follows the team's historically bad offensive performance Sunday. Denver compiled just 134 yards of offense in a 20-3 loss to the Buffalo Bills -- the lowest single-game total for the Broncos since 1992 and the eighth-worst single-game total in the franchise's history.
Asked whether Lock, who is still on injured reserve, could be moved to the roster this week, Fangio said: "It's possible, yeah. ... As far as this week goes, all options are on the table. ... We're just going to make a decision in the next couple days."
So is starting Lock on Sunday against the Los Angeles Chargers one of those options?
"Possibly, yeah," Fangio said.
At 3-8, the Broncos are on pace for their third consecutive season of double-digit losses -- something that has not happened to the franchise since 1965 to 1967. If Lock is put into the starting lineup, he would be the seventh starting quarterback and the ninth change the Broncos have made at quarterback overall since the start of the 2017 season.
Lock has been on IR since the start of the regular season with a right thumb injury he suffered in a preseason loss to the San Francisco 49ers. He did not participate in a full practice again until Nov. 12. The Broncos have until Dec. 3 to move Lock to the active roster or keep him on injured reserve for the remainder of the season.
Lock was one of two second-round picks for the Broncos in April's draft. If he remains on injured reserve, he cannot practice with the team after Dec. 3.
Fangio has repeatedly said that the 12 weeks Lock did not practice affects the rookie's ability to be ready to play. This week will mark Lock's eighth, ninth and 10th full practices since he returned to practice earlier this month.
Although Lock is physically fine to play, Fangio said he's still evaluating whether Lock is ready for game action.
"Just [want to] see some more practice ... just to make sure he's OK, physically, which he is, and that he's prepared mentally and emotionally to play," Fangio said.
Asked about the public sentiment that Lock should play, Fangio said: "I think we need to make the decision we feel is best, understanding everybody's wants, from your group and the group outside, but we need to make the decision we feel is best for Drew and the team, and we will," Fangio said.
In his third start for the injured Joe Flacco, Brandon Allen was 10-of-25 passing Sunday for 82 yards to go with an interception in the loss to the Bills. He was also sacked four times. The Broncos closed out the loss with five consecutive three-and-outs.
On those last five possessions, which totaled 15 plays from scrimmage, the Broncos had all of 2 net yards combined. Allen's interception also ended the Broncos' only drive that made it to the Bills' 25-yard line.
"We were sluggish offensively, we didn't execute very well ... and when we do get a chance, I make the poor decision on a pick," Allen said Sunday. "When you're trying to find completions out there, it's tough, and I obviously didn't do a very good job of it."