The Raiders are poised to pony up for Derek Carr. Last season’s MVP candidate is on the verge of signing a lucrative contract extension worth around $25 million annually which has ramifications for the 49ers if and when they hit the quarterback market in 2018 like many expect.

San Francisco will be linked to Washington quarterback Kirk Cousins as long as long-term contract talks with his current team stay in a holding pattern. Cousins is unsigned beyond 2017 after becoming the first quarterback to get franchised in consecutive seasons in March. The two sides have until July 17 to agree on a new deal, otherwise they won’t be able to negotiate until after the coming season.

Cousins, of course, was drafted with new 49ers coach Kyle Shanahan as his offensive coordinator in 2012 before the Michigan State alum eventually replaced Robert Griffin III as the starter. Washington could decide to slap Cousins with the franchise tag for a third-straight season to pay him the exorbitant amount of $34 million for 2018.

It seems unlikely no matter what kind of season Cousins has in 2017, although Washington team president Bruce Allen won’t rule it out.

A third franchise tag, while highly unlikely, isn’t an impossibility. If Cousins plays well and Washington goes deep into the postseason, Washington may have no choice but to pay the $34.47 million for one more year with Cousins.

Regardless, Cousins can’t lose. He will have made nearly $44 million over two years, and he’ll get $34.47 million or $28.78 million for 2018, or a long-term deal from Washington or someone else.

Carr’s new contact will likely be the richest in league history, setting things up for Cousins (and free agents Drew Brees and Matthew Stafford) to potentially eclipse it next spring, assuming the salary cap rises like it does just about every offseason. Andrew Luck set the bar earlier this offseason when Indianapolis doled out a new five-year, $122.97-million contract with $47 million in guarantees at signing.

The 49ers have a league-leading $66 million in cap space and will have more than enough room to add a franchise quarterback-type contract to their books next year. Cousins is the most likely candidate after it was reported earlier this offseason his preferred long-term destination was San Francisco to reunite with Shanahan.

Another pending free agent option could be Patriots backup Jimmy Garoppolo, who wasn’t traded this offseason despite being bandied about while Tom Brady pledged to continue his career well into 40s for three to five more seasons.

But there’s no precedent for a quarterback playing at Brady’s level at that age, which might behoove New England to hold on to their prized backup with a new contract before Garoppolo hits the open market next March.

The best-case scenario for the 49ers might be to find a long-term quarterback in house. They’re entering 2017 with Brian Hoyer, 31, as the starter after he put together decent showings the lat two seasons.

Hoyer in his last 17 games (14 starts) completed 63 percent of his throws while averaging 238 yards with 25 touchdown passes to just seven interceptions. His quarterback rating: 93.7, which would have ranked 12th among starters last season, ahead of Russell Wilson, Jameis Winston, Eli Manning, Cam Newton and others.

The 49ers signed Hoyer to a two-year, $12-million deal which could increase to $18.5 million with incentives. San Francisco also traded into the third round to draft Iowa’s C.J. Beathard, who has experience in a pro system and toughness Shanahan covets.

In the off chance Beathard ascends to the starting lineup this year, surpassing backup Matt Barkley, the 49ers might wind up in an extremely advantageous scenario. As the Cowboys have shown with Dak Prescott – and the Seahawks previously with Wilson – teams have a huge advantage when they can get strong quarterback play from mid-round picks on rookie contracts.

If Beathard somehow emerged as the next Cousins in his first season, it would allow San Francisco to invest their cap space and draft capital elsewhere, which was a luxury that helped Dallas and Seattle rise to the top of the conference.

That’s the pie-in-the-sky scenario for the 49ers, while it remains more likely they offer Cousins a contract next spring commensurate with Carr’s deal to stay with the Raiders.

But a lot can happen between now and March.