Smiley participates in drills on Monday

Arik Armstead missed this past weekend's game against the Denver Broncos due to a foot injury that has bothered the defensive lineman since before Week 1. He told NBC Sports Bay Area that he has been dealing with plantar fasciitis in his right foot. The injury got worse in the 49ers' Week 2 game against the Seattle Seahawks. "It is improving," head coach Kyle Shanahan told reporters, noting that Armstead will not practice on Thursday. "He was real close to going [against the Broncos]. We thought he did real good in that workout before the game, but we held him back, and it's still the same today as it was on game day. Hopefully, it will be good by