When the San Francisco 49ers visit Tampa Bay on Sunday, they expect to have All-Pro running back Christian McCaffrey in the backfield for the first time this season.

McCaffrey, who was listed as questionable on Friday's injury report, has missed the entire season with tendinitis in both Achilles. He initially hurt his calf on Aug. 6 and was placed on injured reserve prior to Week 2.

But now he's ready to go, and McCaffrey was activated from IR on Saturday.

"We'll take him off IR tomorrow, and then he'll be good to go unless something crazy happens on this plane ride," Shanahan told reporters on Friday. "He should be good to go tomorrow once he gets off IR."

That's welcome news for the 49ers, who have managed a 4-4 record in his absence and come off a bye still as serious contenders to recapture the NFC West and vie for another Super Bowl appearance.

McCaffrey played just 10 combined games with Carolina in 2020 and 2021 but had been remarkably healthy since joining San Francisco in 2022, sitting out just one inconsequential game with a calf injury last season.

It's unclear how much of the game plan would include the 2023 NFL Offensive Player of the Year on Sunday.

Jordan Mason has filled in amply at running back, ranking fourth in the NFL in rushing yards (685) with three touchdowns.

But McCaffrey adds another dimension behind quarterback Brock Purdy and a receiving corps depleted by injuries to Brandon Aiyuk (knee), who is out for the season, and Jauan Jennings (hip), who returned to practice this week. McCaffrey led the NFL in yards from scrimmage (2,023) and rushing yards (1,459) last season and tied for the lead in touchdowns (21).

His potential return complicates a massive matchup for Tampa Bay.

"It's just another weapon we've got to worry about, along with him, Deebo (Samuel), George (Kittle), Purdy as well," Buccaneers coach Todd Bowles said. "You've got to worry about five different guys, you can't just worry about McCaffrey. We've got to be sound defensively, and everybody has to do their assignment because (the 49ers are) talented all over the field."

If McCaffrey returns on Sunday, the season basically begins anew for the 49ers, who are just a half-game behind the NFC West-leading Arizona Cardinals (5-4).

Tampa Bay is completing a brutal back-to-back on a short week. The Buccaneers fell to 4-5 after a 30-24 overtime loss at Kansas City on Monday. Another defeat could drop the Bucs further behind the Atlanta Falcons (6-3) in the NFC South. Tampa Bay has lost three in a row and is off next week.

Buccaneers quarterback Baker Mayfield leads the NFL with 23 passing touchdowns and is second in passing yards with 2,389 despite numerous injuries to his wide receivers. Mike Evans (hamstring) has missed the past two games and is questionable for Sunday's contest, while Chris Godwin is on injured reserve with a season-ending ankle dislocation.

Mayfield said the key on Sunday will be working around a 49ers pass defense led by edge rusher Nick Bosa (hip), who joins Samuel (rib/oblique) in being listed as questionable for Sunday's game.

"The way they rush the passer, they're jetting up field, that's their system," he said. "(Linebacker) Fred Warner is a guy in the second level. Unbelievable player, flies around, really makes a defense go, tough to stop in the run game. (They) play so quickly."

Also questionable for San Francisco are offensive lineman Jon Feliciano (knee) and safety Malik Mustapha (calf). Four 49ers were ruled out -- receiver Chris Conley, defensive linemen Kevin Givens (groin) and Yetur Gross-Matos (knee), and cornerback Charvarius Ward.

Ward is away from the team after the unexpected death of his 1-year-old daughter.

The emergence of tight end Cade Otton has been crucial to the Tampa Bay offense and could help offset San Francisco's aggressive approach. The third-year tight end led the Buccaneers with eight receptions and 77 yards against the Chiefs, and he caught his fourth touchdown pass of the season.

On Sunday, Otton could become the second tight end in NFL history to produce eight or more catches in four consecutive games. Kansas City's Travis Kelce holds the record, as he produced a seven-game streak in 2020.

"It's all Cade," Mayfield said. "(He's) a special player that (is) so smart. He knows where to be, he knows exactly what we're trying to get done within whatever scheme we're calling, run or pass, and he understands everything."

The Buccaneers also listed wide receiver Jalen McMillan (hamstring), safeties Jordan Whitehead (quad) and Tykee Smith (knee), and nose tackle Greg Gaines (calf) as questionable on Friday.

--Field Level Media