MIAMI — The San Francisco 49ers stunned the NFL-watching world when they traded for quarterback Jimmy Garoppolo, until then the successor-in-waiting to Tom Brady with the New England Patriots, in late October of 2017.

Some 27 months later, they are in the Super Bowl.

So are those, in hindsight, cause-and-effect occurrences? Mere happenstance? Something in between?

The proper characterization of that is open to interpretation as the 49ers prepare to face the Kansas City Chiefs on Sunday. It is a quarterbacks league, and San Francisco has been next to unbeatable with Garoppolo in the lineup since trading for him. But he has not always put up the passing numbers of a franchise quarterback since the deal, and the 49ers rolled through the NFC playoffs on the strength of their imposing defense and their productive running game.

Yet Garoppolo’s teammates are quick to defend him and effusive in their praise of him. And Garoppolo vows to be ready if the circumstances of Sunday’s game transform this Super Bowl into a passing duel between him and his far more celebrated Chiefs counterpart, Patrick Mahomes, the third-year pro who was the league’s MVP in his second NFL season.

“As a quarterback, you want to throw it, obviously,” Garoppolo said. “But it’s tough, though. When you’re running the ball for eight yards a carry, moving the sticks play after play, it’s like, ‘Do you really want to pass it?’ I’m in that mind-set of whatever it takes to win. I’ve been like that my whole life. When you’ve got a team of guys like that like we do, it makes you tough to beat.”

Garoppolo totaled only 27 passing attempts and 208 passing yards in lopsided playoff triumphs over the Minnesota Vikings and Green Bay Packers. That would qualify as a pretty good first half of one game for Mahomes. But it worked just fine for the 49ers.

Garoppolo has demonstrated that he is a perfectly capable passer. He threw for 27 touchdowns and nearly 4,000 yards during the regular season. Teammates – from cornerback Richard Sherman to tight end George Kittle – have been quick to defend Garoppolo publicly, and the 49ers say they’re confident that Garoppolo can win the game for them if the Chiefs’ defense pays too much attention to the running game.

Hall of Fame quarterback Kurt Warner said he thinks Garoppolo can be productive if the 49ers choose – or are forced – to rely on their passing game. But that also could result in mistakes being made by Garoppolo.

“I definitely think he can deliver,” said Warner, an analyst for NFL Network. “My biggest thing with Jimmy is that . . . sometimes he misses defenders. His vision gets clouded or he’s so focused on trying to make the throw that he misses guys. And so you’ll see, kind of like the Minnesota game a couple weeks ago, they had two opportunities for easy interceptions, and they made one and they didn’t make the other. I think there will be a few of those plays for Jimmy in this game. I think that’s where he’s at as a quarterback.”

What Garoppolo must do, Warner said, is avoid having one of those errant throws come at a key moment.

“There might be one throw, and that throw can be the difference-making play in a Super Bowl,” Warner said. “And can the Chiefs make that play? Can Jimmy avoid that play?”

Since the trade, the 49ers are 21-5 in games started by Garoppolo, including the two victories in this season’s playoffs. He arrived in San Francisco with two Super Bowl rings from his Patriots tenure as Brady’s understudy. Kittle was a rookie when Garoppolo made his first start for the 49ers late in the 2017 season after the trade. He recalled that when Garoppolo spoke on the team’s sideline during that game, it was immediately clear that he commanded respect.

“Every head on the sideline snapped – coaches, trainers, equipment managers, ballboys, every single player,” Kittle said. “And everyone listened to what he had to say. It was just like the first time in my life I’d ever seen anything like that.”

It had nothing to do with Garoppolo’s New England background, Kittle said. There was no suspicion that he’d brought a sliver of the Patriots’ winning magic with him. It was just Garoppolo’s straightforward approach and dependability.

“It’s just the guy is a leader,” Kittle said. “He doesn’t have a front. He’s not fake at all. Everything he says, he does. All he does is show up and he plays ball. That’s all he does every single time he steps on a football field.”

Garoppolo said he tried to learn his lessons in New England and apply what he gathered from observing Brady. But he wasn’t, he said, trying to be a Brady clone.

“I try not to be anything but myself,” Garoppolo said. “So I think it’s always come naturally to me. As I’ve gotten older and everything, I think it’s become more and more out there. I tried to learn some things from Tom. But when you start doing things that aren’t natural to yourself – these guys out here are pretty smart, so they’ll see right through you if you start acting not as yourself.”

Now he is in a Super Bowl, with the Patriots nowhere in sight and Brady eligible for free agency and contemplating his NFL future. There have been reports that Patriots owner Robert Kraft prompted Coach Bill Belichick to make the Garoppolo trade, and there has been speculation that Brady was not a willing mentor to Garoppolo and their relationship was strained. But Garoppolo says he is thankful for his time in New England.

“Your past is always part of you,” he said. “The Patriots is where I started, really introduced me to the whole program and how different it is than college. I thank everyone over there for everything they did for me. Obviously what they did there got me to this point here. So I think everything’s tied together.”