Colts at Titans, 8:30 p.m. Monday, ESPN

INDIANAPOLIS – He walked into the Indianapolis Colts’ locker room six weeks ago with two career starts and almost no pre-existing relationships.

Jacoby Brissett’s new teammates barely knew his name. How could they be expected to put their fates in his hands?

Now, a month and a half later, walk into that same locker room and ask around. You hear descriptions of Brissett that include terms like “swag.” And teammates speak of him with the kind of respect typically reserved for accomplished veterans.

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Brissett’s ability to keep the Colts afloat — he’s 2-2 as a starter — while Andrew Luck’s shoulder heals is remarkable in and of itself.

But equally impressive is Brissett’s capacity to not only quickly integrate himself into the locker room but to also establish credibility with his teammates. The Colts not only believe in Brissett. They’re following his lead.

Yes, a 23-year old quarterback who walked through the door in September has already become one of this team’s leaders. Do you understand how incredibly difficult that is to do in the NFL’s alpha-male environment?

“I’ll tell you right now, I didn’t even realize he was that young,” left tackle Anthony Castonzo said, wearing the surprise on his face. “That’s really, really young. He doesn’t carry himself that way at all.”

This team had no reason to believe in Brissett. Certainly the struggles of Scott Tolzien in the season opener meant players would be open to an alternative. But that doesn’t mean Brissett faced no challenges in taking ownership of the offense.

For Brissett, there was a fine line to walk. How do you come into a delicate situation following an abrupt trade, exuding confidence but also just the right amount of humility?

Arrogance can be a turnoff no matter its source. Arrogance from the new guy? Forget it.

“He came in without a big head,” nose tackle Al Woods said. (This would be a good place to point out that commanding respect from a veteran defensive player is one of the highest compliments a quarterback can receive. The quarterback is generally out of sight, out of mind for them).

“He was more of a guy who came and said, ‘I’m going to let my work speak for itself.’ That was the thing that really hit home for a lot of us. He didn’t say much when he got here. You walk in here and you would see him with his head down, in the playbook. He basically would be sitting there with the playbook, look up at the clock and then run out to practice. You can’t do nothing but respect that.”

But then there’s still the matter of getting teammates to believe in you. They might like you, but that doesn’t mean they trust you.

For any backup quarterback, “the biggest thing is getting his team to believe,” offensive coordinator Rob Chudzinski said. “When he calls a play, when he starts a drive, when it’s a critical time in a 2-minute situation, a third down, red zone, whatever it is, they (need to) say, ‘Hey, this guy is going to get it done for us.’

“And that’s what Jacoby has been able to do with his teammates. And that’s the biggest hurdle and the first hurdle.”

Take it from a guy who was also pretty good at this when he first took over as the starter.

“Guys when (they) walk in the huddle want to see a quarterback that’s calling a play that has the confidence behind it that that play will work,” quarterback Andrew Luck said. “He does a good job of that. And he earns that in practice and he earns it in the meetings. It doesn’t just happen with the click of a finger.”

It happens through Brissett hitting all the right notes with respect to his off-field dealings with his teammates. And it happens through them observing his unrelenting work ethic.

But there’s another element that might supersede those: Making plays.

That, after all, is a quarterback’s chief responsibility. There have been many ups and downs. Look, the Colts rank 25th in yards per game. Brissett’s still a 23-year backup quarterback. But then you see him avoid two oncoming rushers, roll to his right and throw a pass 50 yards in the air to T.Y. Hilton like he did against San Francisco this past week. Plays like that just solidify everything Brissett displayed leading up to the moment.

The quiet confidence. The work. The innate leadership ability.

“He has a lot of swag to him,” Hilton said. “Just watching him out there, you can see it.”

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He’s also unflappable. When those inevitable negative plays come — the overtime interception against the 49ers, for instance — Brissett predictably bounces back.

“He’s pretty much unfazed out there,” Castonzo said.

Now, Brissett takes the Colts into a key in-division road game against the struggling Tennessee Titans, his first Monday night appearance. He’s trying to get the Colts to .500 in their first AFC South contest of the season. It’s a huge game for a team that has struggled to eke out wins over San Francisco and Cleveland.

And the Colts have a quarterback they’re ready to follow. Now, they even know his name.

Follow IndyStar Colts Insider Stephen Holder on Twitter: @HolderStephen.