Huntley was injured on the first drive of Atlanta's 21-18 loss to New Orleans on Sunday, when he had one carry for two yards.
Smith was shocked at what happened after Huntley injured his Achilles on the second play of the game.
"It was one of the most unusual things I've seen. He injured his Achilles the second play and didn't go down. He stayed in there and I don't know how the hell he did it, to be honest," Smith said. "He went in there, played a snap, actually made a block in pass protection and then jogged off the field. I asked him this morning, I don't think I've ever seen that. And he said, 'I knew you wanted to go no-huddle early and I didn't want to come out.'
"I'm like, 'You were injured there. You could have gone down.' I don't know how the hell he did it. I feel awful for him."
Huntley, 24, had become a strong part of the Falcons' run game, ranked third in the NFL.
On Monday, Huntley said in a tweet that he's in good spirits and vowed to come back.
Please do not feel bad for me I'm in a good state of mind I'm locked in I been down before but never out come back will be something to write about remember the tweet #dukeslatt 💪🏾💪🏾 https://t.co/sYVNoUYEA6— 🚂 Huntley for 6️⃣ (@1DukeHuntley) December 19, 2022
Huntley, who played at Ball State, began the season on Atlanta's practice squad and was elevated the active roster multiple times before signing a two-year deal with Atlanta on Oct. 3, after the team placed Patterson on injured reserve.
Huntley had acted as part of a one-two running back element with Allgeier while Patterson was gone, including rushing for a career-high 91 yards against Carolina on Oct. 30.
With Huntley out for the season, the Falcons will have Patterson, Allgeier and Avery Williams as running backs on the active roster.
Smith also said that the team would monitor defensive coordinator Dean Pees as the week goes on after he was treated at a New Orleans hospital Sunday following a collision with Saints returner Rashid Shaheed during pregame warm-ups. Pees flew back with the team to Atlanta later that night was back at work on Monday.
"I'm just glad he's all right," Smith said.