Brock Purdy isn't the only 49er who can improvise on the fly: Coach Kyle Shanahan routinely does it and oftentimes, the improvisation yields successful results.
On Thursday, 49ers offensive line and run game coordinator Chris Foerster was asked about San Francisco's offensive success and gave Shanahan credit for thinking outside of the box.
"If you've seen the call sheet, if you've seen it held up, there's a lot of writing on that," Foerster told reporters. "He says, 'No, that's what they're doing, this is what we're going to call.' and he calls something based on what he sees in the game that isn't even on the list.
"And they're usually big hits and big plays because he just knows what is going to work ... I've been amazed since I've worked with him and I don't stop doing that. It's just how he does it, and it's just his grasp on what he's doing."
Foerster gave three examples of Shanahan's uncanny ability to freestyle successful plays: George Kittle's catch up the sideline against the Arizona Cardinals in Mexico City, another Kittle touchdown against the Washington Commanders in Week 16 and Deebo Samuel's 74-yard touchdown reception against the Seattle Seahawks in the NFC Wild-Card Game last weekend.
Because of how rare it is to go off-script, Foerster is even more impressed and "marvels" at Shanahan's ability to make the right call at the right time.
"He's really good at it ... he has a pretty good grasp on what to go to in his offense and how to do it, so it's a real pleasure for a guy like me to work for him because when you do that, he has such good direction on how he wants you to go, so when either you're a player, whether you're an assistant coach, whoever you are, there's a great leadership or direction, as here's what you have to do to do your job," Foerster added.
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Foerster isn't the only one impressed with Shanahan's improvisation skills -- Purdy, the 49ers' rookie quarterback, lauded Shanahan's ability to adjust at a moment's notice.
"Yeah, there's times where he adds things throughout the game, things that we haven't even gone over at practice or that are off script, because he's thinking about things as well, so he'll tell us going into half or for the next drive, and he's like, 'Hey, I'm thinking of this,' " Purdy told reporters. "And we're like, 'Dang, that makes sense,' and so it's pretty cool to see how he thinks as a coach and everything how he calls plays, but it definitely takes everybody."
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As the 49ers continue to prepare for their NFC Divisional Round matchup against the Dallas Cowboys on Sunday in another chapter of their historic rivalry, both sides surely will pay attention to what the other team will do on offense.
For the Cowboys, they have to be extra vigilant and if they aren't careful defensively, Shanahan could spring a play that Dallas isn't expecting.