The unbeaten 49ers go to Atlanta without Mike Evans, Nick Bosa or Deebo Samuel

The San Francisco 49ers put a 6-0 record on the line at Atlanta on Sunday at 1 p.m. ET on Fox without their top receiver, their best pass rusher or Deebo Samuel Sr. The team ruled out Mike Evans (Achilles tendinitis), Nick Bosa (calf) and Samuel (hamstring) on Friday, ESPN reported, and confirmed Sunday that Christian Kirk is active for the first time this season.

Kyle Shanahan told reporters the 49ers were likely to go into the game with fewer than the maximum 48 players on the game-day roster, even after practice squad elevations. The team had talked with some players about lining up out of position if more injuries hit.

"I don't think ever in my career [has that happened]," Shanahan said, according to ESPN. "It's a unique situation."

The receiver list is where it gets ugly. Along with Evans and Samuel, San Francisco is already without Ricky Pearsall (knee), De'Zhaun Stribling (ankle) and Demarcus Robinson (ankle), per ESPN. Kirk hurt a calf in the first days of training camp in July and has been on injured reserve ever since. The 49ers released defensive end Ogbo Okoronkwo on Friday to open a roster spot for him.

"I've played a lot of football and have got a lot of experience," Kirk said Thursday. "This week has just been treating every rep like a game rep."

Evans was on his way to a big night against Washington on Monday before the Achilles flared up just before halftime, and he did not practice this week. Bosa has not played since before Week 3, when he hurt his calf during a walk-through. Shanahan said Bosa felt sore the day after saying he was close, which "surprised all of us." That leaves Mykel Williams, Romello Height, Keion White and Khalid Kareem to chase Atlanta's quarterback.

Cornerback Upton Stout is active after returning to practice Friday, the team said. Linebackers Luke Gifford and Garret Wallow and safety Marques Sigle are also out.

The Falcons (2-4) have their own holes. Running back Brian Robinson Jr. (hamstring), cornerback Billy Bowman Jr. (hamstring) and linebacker Divine Deablo (forearm) are inactive, according to ESPN. Former Falcons head coach Raheem Morris now runs the 49ers' defense. San Francisco has its bye next week.