SANTA CLARA, Calif. -- By the time the San Francisco 49ers sat down for their team meeting Friday morning, word of the acquisition of star running back Christian McCaffrey had already spread through the locker room.

Which explains, at least in part, why coach Kyle Shanahan didn't address it at all until the waning moments of the meeting. When he did, Shanahan harked back to 2019, when San Francisco made a big trade to acquire receiver Emmanuel Sanders to buoy the then-6-0 Niners' chances at winning a Super Bowl.

And while the Niners remain well aware that they're just 3-3 at a similar stage, the message Shanahan and general manager John Lynch sent to the team Friday was the same.

"The way him and John looked at is that they have so much confidence in what this team can do and that this team is ready to win now that they want to go all-in," fullback Kyle Juszczyk said. "It wasn't that we necessarily had to have someone at that position, it was just, 'We feel like we can do some really special things, so why not add that weapon to what we feel like we've already got?'"

The Niners and Carolina Panthers officially completed their trade Friday morning with San Francisco sending second-, third- and fourth-round picks in 2023 and a fifth-round selection in 2024 to Carolina for McCaffrey.

In San Francisco, the hope is McCaffrey, combined with some improvement from within, can get the Niners over the hump after they came up short in their pursuit of a sixth Lombardi Trophy in 2019 and again in 2021.

"You only do this when you have a belief in your team as it's constructed," Lynch said. "We understand we have a lot of work to do, and this isn't a magic pill that's going to fix all of our ills as a team. We've all got to get better, but we do still very much believe in this team, and that's why we took a swing at an excellent football player."

McCaffrey arrived in the Bay Area on Friday morning and was quickly plugged into the team's daily activities. After completing his physical, he got a locker and a helmet and joined the light Friday practice midstream, though he didn't take any reps in team drills.

It's not yet clear whether McCaffrey will play Sunday against the Kansas City Chiefs, but he's already lobbying to be active, according to Lynch. McCaffrey said the decision will be up to the team on whether he plays, with Shanahan adding that McCaffrey's status has more to do with whether he can quickly learn enough of the playbook to contribute and nothing to do with how he's feeling physically.

Chiefs coach Andy Reid said his team will prepare with the expectation of going against McCaffrey.

"We know he's a talented guy. I'm sure they'll work him in," Reid said. "We're expecting that. You prepare for what he does well, and Kyle will use him in what he does well.''

McCaffrey, who missed 23 games over the prior two seasons because of injury, said he's feeling good. He clearly is excited to join a Niners team that plays its home games 15 minutes from where he went to college at Stanford and is coached by Shanahan, whose father, Mike, coached McCaffrey's father, Ed, for nine seasons with the Denver Broncos.

"I've obviously watched them for a long time," McCaffrey said. "In my opinion, [it's] the best run game and one of the most explosive offenses in the league. And I think you just go down the roster and you look at all the guys, I think that's the thing I'm most excited about. Just getting in the locker room, getting to meet the guys. But how could you not want to play here as an offensive weapon? I'm extremely fired up."

Regardless of whether McCaffrey's debut comes Sunday or in Week 8 against the Rams, the Niners are pleased that he will be playing for them and not on the other side next week in Los Angeles.

The Rams made a habit of trading for big names en route to last year's Super Bowl victory and were the Niners' closest competition to acquire McCaffrey. That strengthened San Francisco's desire to close out deals such as this as fast as possible.

That wasn't the primary reason the Niners traded for McCaffrey, of course, but it didn't hurt.

"It's definitely a bonus," Shanahan said. "I think everybody would love the opportunity to have a player like Christian. So, I think everyone looks into it but it's also nice to keep a good player away from the team that we have to compete with year in and year out."

The Niners did get the deal done, albeit at a significant cost. Lynch said the trade began to come together when the team was in West Virginia for a week of practice last week.

And while the Niners will get McCaffrey for a little less than $700,000 for the rest of this season, his salary-cap number jumps to $12 million in each of the next three years. That's a hefty contract for a running back, even one as talented as McCaffrey.

Because McCaffrey also has no more fully guaranteed money in his contract after this year, a reworked deal could be in the offing. For their part, Shanahan and Lynch made it clear that they view McCaffrey as a 49er beyond this season.

"It's not every day that you get a guy like Christian at the minimum," Lynch said. "And that's essentially where we got him. But he still has years on his contract after that. I think we're taking it step by step, but obviously that helps to know that the guy's got some years after this year and it's not just an 11-game, for lack of a better word, rental."

McCaffrey has long been on San Francisco's radar, dating to the 2017 NFL draft when coach Kyle Shanahan was a big proponent of the Stanford product. The Niners ended up selecting defensive lineman Solomon Thomas, McCaffrey's Stanford teammate, with the No. 3 overall pick.

Shanahan said Friday the Niners weren't close to drafting McCaffrey with that pick (though he might have been in play had the team traded down further) and that he and Lynch joked with the running back that they were just waiting until everything was in place before acquiring him.

"The first thing I told Christian was that this was our plan all along," Shanahan said, laughing. "And that's why we wanted to build a D-line and build our defense right away and we'd get him five and a half years later."