Colin Kaepernick played six seasons for the 49ers, starting 58 games, before becoming a free agent last year. (Marcio Jose Sanchez/Associated Press)

The San Francisco 49ers suffered a devastating blow Monday with the confirmation that starting quarterback Jimmy Garoppolo tore an anterior cruciate ligament in his left knee the day before, ending his season. With San Francisco suddenly down to just C.J. Beathard at quarterback, the team needs to add another player to bolster the position, prompting calls for the Niners to bring back a familiar face: Colin Kaepernick.

The free agent quarterback has been out of the NFL since March 2017, and he has filed a grievance against the league, accusing team owners of colluding to punish him for being the originator of players' protests of racial injustice during the national anthem. While Kaepernick’s story has gained renewed attention in the wake of a major Nike ad campaign for which he is the centerpiece, he reportedly has continued training in hopes of returning to the league.

The connection to the 49ers is obvious: Kaepernick spent his six-year NFL career with the team after it made him a second-round draft pick in 2011, and he led the Niners to their most recent Super Bowl appearance in 2013, nearly pulling off a comeback victory over the Baltimore Ravens. Since then, the team has gone through some managerial changes, and the current head coach, Kyle Shanahan, and general manager, John Lynch, parted ways with Kaepernick shortly after they were installed.

The 49ers' owner, though, has spoken favorably of Kaepernick’s aims in his protests, even as the demonstrations, which a handful of players have continued in the quarterback’s absence, remain a thorny issue for the NFL. So owner Jed York might be on board with a reunion — particularly in light of Nike’s commercial success since launching its campaign — and others have made the case that it should happen.

“Messrs. York/Lynch/Shanahan: End the shameful blackballing of Colin Kaepernick by the NFL,” the sports editor of the San Francisco Chronicle, Al Saracevic, wrote Monday in an opinion piece for the newspaper. “Put a respectable quarterback on the field and see if you can’t resurrect a season gone south. Do the right thing.”

Naturally, many of the public calls have come from social media, including a Twitter post by “Bones” actor and Niners fan Pej Vahdat, who told his team, “Don’t be stupid we need another QB now and Kaepernick is ready!”

Unfortunately for those hoping the 49ers will bring back Kaepernick, the team is considering other options to back up Beathard, a third-round pick last year who made seven appearances as a rookie, including five starts, and completed 54.9 percent of his passes for 1,430 yards and four touchdowns with six interceptions for a 69.2 passer rating. San Francisco promoted another second-year quarterback, Nick Mullens, off its practice squad, and Shanahan said Monday that he is bringing in three veterans, Kellen Clemens, T.J. Yates and Tom Savage, for tryouts, with a fourth, Matt Moore, also a possible candidate.

“I made that decision [to not pursue Kaepernick] because of the style of offense we wanted to go with,” Shanahan said. “That’s kind of what I said last year. It’s the same situation now. I always look into what style of offense I want to do, what style of offense we’ve been doing for the last two years.

“When you start to get to these quarterbacks we’re talking about, C.J.’s our guy and we have Nick Mullens backing him up. When you get into a third or fourth guy, whoever that is,” the coach continued, “you’d like to bring in guys who you felt you didn’t have to change much of your offense for.”

That’s been one of the knocks on Kaepernick — he excels more in mobility and arm strength than in dissecting defenses and going through his receiver progressions from the pocket, and that skill set generally does not fit with what most NFL coaches want from their quarterbacks. On the other hand, he posted solid passing statistics in his most recent season, throwing for 16 touchdowns against just four interceptions with a 90.7 rating, and while he lost 10 of his 11 starts, the team also lost all but one of the games he didn’t start, indicating that Kaepernick’s play was hardly the biggest of the 2016 49ers' problems.

In addition, the auditions for the likes of Clemens, Yates and Savage come as yet another reminder that many quarterbacks with far lesser résumés than Kaepernick’s have been signed by NFL teams in the time he has been out of work. In this case, all three have notably worse career marks in major categories such as completion percentage, passer rating and yards per attempt, with very little of Kaepernick’s ability to damage defenses on the ground.

Nevertheless, it is all but certain that the 49ers won’t be giving some fans what they want in signing Kaepernick. That may not mean, though, that his only path back to the NFL is being closed, according to a lawyer who is helping the quarterback with his grievance case.

Of a potential return to the field by his client, attorney Mark Geragos recently told TMZ Sports, “I would just say, ‘Stay tuned,’ that next week there may be some news.” Geragos hinted at the Oakland Raiders and New England Patriots as possible suitors for Kaepernick’s services.

Geragos added that Kaepernick has been watching the Dolphins, out of support for Miami’s Kenny Stills and Albert Wilson, who have been the only two NFL players kneeling during the anthem this season. A few others have raised their fists or remained off the sideline during performances of the anthem, but apart from President Trump’s criticism of the Nike campaign, player demonstrations have largely stayed out of the news through the first three weeks of the regular season, undoubtedly to the league’s relief.

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