Keeping the main thing the main thing is generally sound advice. And as it pertains to Miami Dolphins Pro Bowler Tua Tagovailoa, who’s now suffering from at least his third concussion in the past two years after getting knocked out of Thursday night’s loss to the Buffalo Bills, the focus should be on his immediate and long-term health.

Reporters asking sleep-deprived Mike McDaniel for updates about his quarterback’s well-being Friday morning – while floating various football scenarios – attempted to tread respectfully as the head coach tried to suppress any frustration while acknowledging the import of such questions, which admittedly seemed to trigger him, even though they were clearly trivial in comparison to Tagovailoa’s recovery.

“The driving force behind any sort of move – let’s say playing any time, let’s say IR (injured reserve), let’s say whatever those things are,” McDaniel said, “the absolute, most important opinion is, the most important person in this whole equation is Tua. His opinion, and what he wants to do with his life and his career – coupled with the experts in neuroscience – those are the driving forces behind those actions.

“I have zero idea what any sort of timeline is. And I’m actually extremely motivated to be in the gray, because I’m extremely motivated to do right by the person that we’re talking about.”

But, at some point, the well-being and course of a franchise that invested so heavily in Tagovailoa over the summer could come into serious question.

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Here are five reasons why the Dolphins seem likely to be in major trouble if their quarterback can’t play again this season … if ever.

What free agent quarterbacks could Dolphins sign in 2024?

Suboptimal as it is, McDaniel admitted the process of adding another arm to Miami’s roster is already underway, though he expects to move forward with Skylar Thompson as his starter with journeyman Tim Boyle likely to be promoted from the practice squad.

“The team and the organization are very confident in Skylar,” said McDaniel. “That being said, we will bring in someone – we're just evaluating the pros and cons for the different situations and getting through all those possibilities to do the best thing for the team. As it stands today, I'm expecting that Skylar is the next man up."

But who might the newcomer be?

Ryan Tannehill, 36, Miami’s first-round pick 12 years ago, has a Pro Bowl on his résumé and is the most accomplished passer on the free-agent market. His relative accuracy (64.3% career completion rate), athleticism and experience might make him a good fit in McDaniel’s offense. However his performance steadily declined over his final three seasons with the Tennessee Titans, which is probably a large reason why he remains unsigned.

Other notable free agent names include Blaine Gabbert, Brian Hoyer, AJ McCarron and Trevor Siemian – none obviously the caliber of player who could come close to filling Tagovailoa’s void.

Mike White, who spent last season with Miami and started seven games for the New York Jets over the 2021 and ’22 campaigns, is semi-available, currently toiling on the Bills’ practice squad after being released by Miami in August.

Still, not much to get excited about here in terms of potential short-term fixes.

What free agent quarterbacks could Dolphins sign in 2025?

The notion that Tagovailoa might have to prematurely retire isn’t a new one but is an unavoidable thought, former players, media members – probably even teammates – openly wondering if it’s in his best interest to walk away given he also had a concussion while playing collegiately for Alabama. But were that to happen, well, Dak Prescott ain’t walking through that door after becoming the league’s first $60 million man last weekend.

Naturally, veterans and even younger, promising (but unproven) passers seem to be increasingly available when the annual free-agent market throws open its doors every March. But with Prescott now locked up by the Dallas Cowboys, who weren’t going to invite what surely would’ve been a record-setting spending spree on last season’s runner-up for league MVP, next year’s crop is scheduled to feature the likes of former Fin Jacoby Brissett, Sam Darnold, Justin Fields, Joe Flacco, Jimmy Garoppolo, Taylor Heinicke, Mac Jones, Trey Lance, Drew Lock, Marcus Mariota, Mason Rudolph, Carson Wentz, Russell Wilson, Zach Wilson and Jameis Winston.

A few former franchise quarterbacks in that bunch … but certainly no one who’s likely to fill that bill again.

Which quarterbacks could the Dolphins draft in 2025?

This is yet another premature assessment in numerous ways – both as it pertains to Tagovailoa’s future and assessing next year’s draft class at the quarterback position. But if Tua isn’t available to the Dolphins – and given the apparent dearth of proven commodities likely to be in the free-agent pool – the draft might be the most viable potential pathway to a replacement.

There doesn’t appear to be a generational prospect coming out of college next year, which means a talented Dolphins team that reached the playoffs in 2022 and ’23 and is built to win now probably wouldn’t have to pay through the nose to get into position for one, to the degree it would even be necessary. Georgia’s Carson Beck, Texas’ Quinn Ewers and Colorado’s Shedeur Sanders currently project as first-round passers.

Still, that scenario would likely mean Miami wouldn’t be importing a player with potential comparable to that of Tagovailoa, the No. 5 overall selection in 2020 and a player who’s begun fulfilling his potential under McDaniel’s tutelage.

What would it cost to release Tua Tagovailoa?

Perhaps the nightmare scenario – again, completely premature – occurs if Tagovailoa wants to continue playing but the Dolphins don’t think he should. If the team was forced to release a player it signed to a four-year, $212.4 million extension this summer, it would incur a dead cap hit of nearly $84 million. That figure would be ameliorated to some degree by a post-June 1 release designation or if Tagovailoa retired voluntarily. Regardless, it would be a very expensive and unanticipated divorce.

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Would a quick rebuild be possible if Tua Tagovailoa leaves?

Doesn’t seem like it?

The aforementioned factors suggest it would be challenging to replace Tua. But even if GM Chris Grier wanted to start offloading other assets to facilitate a rebuild or attempted to engineer a swap for an accomplished veteran passer, it’s obviously going to be very tough. Miami’s most attractive assets, WRs Tyreek Hill and Jaylen Waddle, both signed significant extensions over the offseason and would incur cap hits of at least $15 million in a trade while stripping the offense of one of its primary assets. Youngsters like S Jevon Holland or RB De'Von Achane would be much easier to move contractually, but their (currently) low cap figures are a significant part of what make them appealing building blocks.

Again, the main thing is the main thing, and who doesn’t want Tagovailoa to lead a happy, healthy life? If that means safely extending his career, so much the better. But it’s quite possible that the quality of his health might be inversely related to the Dolphins’.

Follow USA TODAY Sports' Nate Davis on X, formerly Twitter, @ByNateDavis.