Here's what we know: Aaron Rodgers has a broken collarbone and there's a chance he'll miss the rest of the season. Here's what we also know: The only other quarterback on the Packers' roster is 2015 fifth-round pick Brett Hundley, who before Sunday had thrown a grand total of 11 passes in two-plus NFL seasons.

There's also Joe Callahan, the second-year quarterback out of Wesley College who is currently on the practice squad, though it's certainly more likely that the Packers look outside the organization to find a veteran to replace Rodgers. And while Hundley looked capable against the Vikings on Sunday, Twitter wasted little time speculating about better, older options. At the top of the list, our CBS Sports colleague and Jim Nantz's booth mate ...

Tony Romo: He retired this offseason and promptly took a job with CBS, where he has been amazing as a color commentator. We're not just saying that because we're all part of the CBS Sports family -- the man had made a weekly habit of predicting plays. But Romo is also just 37 years old, which is hardly old by today's NFL quarterback standards. There's also this:

And as SI.com's Jonathan Jones wrote in April and revisited on Sunday, Romo is would probably love an opportunity to play for a contender.

Because this is Twitter -- and this is how Twitter works -- opinions are everywhere:

Then there's this, from our colleague and Cowboys fan Jared Dubin:

Colin Kaepernick. Every time there's an opening for an NFL quarterback, Kaepernick's name is going to come up. He's been a free agent since the spring and to our knowledge he hasn't worked out for a single solitary team in that time. Meanwhile, former 2012 first-round pick Brandon Weeden, who is 6-19 as a starter and was signed earlier this month by the Titans after Marcus Mariota went down with an injury, is the latest to concede that Kaepernick is good enough to be on an NFL roster.

"He's had a heck of a career," Weeden said two weeks ago. "He played in a Super Bowl. Obviously, he's done a lot of really good things. I think us as players, we all kind of firmly believe that he's a good enough player to play in this league."

Weeden's remarks come weeks after Tom Brady spoke about Kaepernick on "CBS Sunday Morning".

"I've always watched him and admired him, the way that he's played he was a great young quarterback," Brady told Norah O'Donnell. "He came to our stadium and beat us and took his team to the Super Bowl. He accomplished a lot in the pros as a player. And he's certainly qualified and I hope he gets a shot."

Incidentally,  Aaron Rodgers told ESPN's Mina Kimes in August that "I think [Kaepernick] should be on a roster right now. I think because of his protests, he's not."

Added bonus: Kaepernick, who was born in Milwaukee, grew up a Packers fan.

Kaepernick was also a huge fan of the guy Rodgers replaced ...

Brett Favre: We're joking but Favre's name came up frequently on Twitter (though we would have to imagine most of those people were joking too, right? RIGHT?!).

Favre, who was inducted into the Hall of Fame in 2016, just turned 48 and hasn't played in an NFL game since 2010 when he started 13 games for a Vikings team that went 6-10. The season before, however, a then-40-year-old Favre led the Vikings to a 12-4 record and all the way to the conference championship game where they lost to the Saints.

We can't envision a scenario where Favre hangs up his Wranglers though it's not the craziest thing we've seen.

In addition to Romo, Kaepernick and Favre, here are other options which, depending on your perspective, may seem more or less insane (seriously, is Robert Griffin III better than Kaepernick or Romo -- or even Favre?):