HOUSTON -- Over the course of 60 minutes Sunday afternoon, the Arizona Cardinals' 2017 season ended and their 2018 season began.

What could've been the game on which another mediocre season pivoted toward a possible playoff run instead became the game that all but assured the Cardinals that they'd be on their couches watching the playoffs for a second straight January. Arizona went to Houston with a 0.2 percent chance of making the postseason, according to the ESPN Football Power Index.

But the Cardinals’ 31-21 Week 11 loss to the Texans at NRG Stadium shrunk the team's possibility of making the playoffs to even smaller than that. In less than two years, Arizona has gone from playing in the NFC Championship Game, a game short of Super Bowl 50, to losing to the formerly 3-6 Texans, who came into Sunday’s game riding a three-game losing streak.

It has been a steady decline, one marred by questionable personnel choices, poor coaching decisions and injuries that have ravaged the roster. But, nonetheless, the Cardinals have continued to sink, losing back-to-back games for the eighth time under coach Bruce Arians. And yet, Sunday may have been only the beginning of the toughest stretch in the Arians' era -- one that may come to define the 65-year-old's legacy, which began with 34 wins in his first three seasons in Arizona while he changed the culture of an entire franchise -- when Arizona hosts the Jacksonville Jaguars, the Los Angeles Rams and Tennessee Titans.

The rest of this 2017 season doesn't matter anymore. Sunday’s game marked the end of this season and in turn the first building block for 2018.

Quarterback Blaine Gabbert showed he should not just be the Cardinals’ starting quarterback the rest of this season, but that he’s their long-term answer at a position that has been such a major question mark for a franchise for years.

Regardless of what happens for the rest of 2017, it’s time the Cardinals start their rebuild. Piece by piece. Position by position. Coach by coach.

Arizona is 4-6 with a home game against the Jaguars coming up a few days after Thanksgiving. A loss would create the first three-game losing streak in the Arians era.

With six games left, Arizona will face four teams that are currently in the playoffs: Its next three opponents and the Seahawks in the season finale. The Cards also still have a cross-country trip left on their schedule, when they fly to Washington in Week 15. They've won just one of their four trips East of the Mississippi River this season so far (at Indianapolis).

With the playoffs all but out of the question -- and the Super Bowl an afterthought -- the question must be raised: Will this be the end of the big three of Arians, Carson Palmer and Larry Fitzgerald?

While plenty of signs point to yes, the big three are done -- there's also a possibility that the trio could return for one more season and give their deflated Super Bowl hopes one last push with a healthy David Johnson, who has been out since Week 1 with a fractured wrist.

Arians' future with the team will likely come down to his decision on whether to return for the final year of his contract. It's difficult to see team president Michael Bidwill firing Arians, who signed a four-year extension in 2015, putting him under contract through 2018 with a team option in 2019.

But Arians will have plenty to evaluate after the season.

Reports surfaced during each of the past two years that Arians was planning on retiring following each season. He returned for 2017, and on Oct. 24, in response to a report that he was retiring after the season, Arians tweeted that "Nothing could be further from truth."

A source told ESPN that Arians has yet to make up his mind on his coaching future. However, among all the factors that'll be on the periphery of his decision -- his family's input, the roster, what Palmer and Fitzgerald do -- the most important is still his health. Arians told ESPN in July that he wants to coach in 2018. If he has to retire, he said, that means his health isn't good. More than midway through the season, Arians hasn't had a health scare. Through November last season, he had two such scares.

While Arians hasn't committed to coaching in 2018 or announced his plans to retire, his health hasn't been a public storyline this season, and the addition of a grandson this summer and the idea of lowering his stress level while enjoying more healthy family time in Georgia -- with some more golf thrown in -- might end up winning the battle inside Arians' heart.

Palmer, who once was a strong candidate to retire after the season, is an unknown at this point. He was expected to retire after last season but surprised some by returning after taking a month to evaluate his health. Palmer's 2017 season ended in Week 7 in London when he broke his left arm. That could, however, be the reason Palmer returns. He's not only hungry for a championship, but when the season ends, he'll be 38 and he may be as fresh as he has ever been heading into an offseason.

Also, a contributing factor for Palmer could be his contract. His $12.5 million salary in 2018 isn't guaranteed by the team, and he's scheduled to earn a $1.5 million roster bonus on April 1.

Should Palmer decide to retire, it's possible Fitzgerald will follow suit, even though he signed a one-year extension on Friday that will keep him under contract with the Cardinals through the 2018 season. However, that contract deal doesn't mean he’ll return for 2018. It just means if he does decide to play another season, it’ll be in Arizona.

Fitzgerald wouldn’t directly address his football future after Sunday’s game.

“My only focus is on Jacksonville,” Fitzgerald said. “We lost a tough one [Sunday] and we got a really, really, really good defense coming in home this weekend. Two good defenses following them. We got to focus on that and that’s where all my attention’s focused.”

When asked if that meant his decision wasn’t made, Fitzgerald continued to skirt the question.

“That means I’m focused on the next game,” he said. “We’re in the midst of the season. It’s a team game. It’s not about anyone individual about what they’re doing or not doing. That’s where I’m going to keep the focus.”

That leaves Fitzgerald, like Palmer, as a wild card. Fitzgerald hinted in 2016 he wouldn't be around long enough to catch Tony Gonzalez for second on the NFL's all-time receptions list, which he'd likely do in 2018. Gonzalez has 1,325 career catches and Fitzgerald has 1,194 after Sunday’s game, putting him 131 behind passing Gonzalez. He's still playing at an elite level, having led the NFL with 107 catches in 2016 and is on pace for another 100-catch season in 2017.

Should the Cardinals lose Arians, Palmer and Fitzgerald, they'll be setting out on a complete rebuild. Arizona won't be able to wait a year to begin embarking on it. With Johnson returning from a fractured wrist and still in his prime, the Cardinals will have to work overtime on putting the right pieces around him to start winning as soon as possible. That started Sunday with Gabbert and undrafted rookie Ricky Seals-Jones showing a glimpse of his potential with a two-touchdown performance.

Defensively, Arizona has a long-term foundation in cornerback Patrick Peterson and outside linebacker Chandler Jones to build around. If the Cardinals don't move quickly during the offseason to begin the potential rebuild, they'd be squandering both players' prime years. Rookie Budda Baker’s performance Sunday, which included a strip-sack, two fumble recoveries and 12 tackles, was proof he can shine on an NFL stage.

And depending on where the NFL sets next year's salary cap, the Cardinals could be in either a great position or an even greater position.

Estimates have the cap around $178 million, which would give the Cardinals approximately $33.8 million in cap space before a slew of potential moves that could open up even more cap space and allow the Cardinals to not just be comfortable in free agency but to take risks.

If Palmer retires, his departure will add $14 million of cap space. If right tackle Jared Veldheer and left guard Mike Iupati are released or retire, they'll add a combined $10.6 million of cap space. Both players carry hefty cap hits and Veldheer was slow to adjust to his new position at right tackle before moving to left tackle after D.J. Humphries’ recent injury, while Iupati has spent most of the season on injured reserve and is unlikely to return. Neither of their salaries are guaranteed for next season. Added up, that would inject $24.6 million of addition space to Arizona's coffers, making approximately $58.4 million available.

With at least that much cap space, the Cardinals could, in theory, afford to make a run at one of the few starting-caliber free-agent quarterbacks in 2018, or back up their money truck for a star receiver to replace Fitzgerald or offensive linemen to protect whomever they put behind center.

But Gabbert showed enough in one game to make the Cardinals ponder their future now. The rest of this season should be Gabbert’s to prove himself. If he continues to play as he did in Week 11 -- 257 yards, three touchdowns and two interceptions (both of which came in the fourth quarter) while completing 67.6 percent of his passes -- it would make little sense to not build the future around him as the quarterback, regardless of what Palmer does.

Arizona could also have as many as nine draft picks in 2018 -- five assigned already and potentially up to four compensatory picks. With 20 unrestricted free agents scheduled to hit the open market, Arizona will have plenty of areas to address, including quarterback with both Drew Stanton and Gabbert entering the offseason as unrestricted free agents, and receiver with Fitzgerald, John Brown, Jaron Brown and Brittan Golden scheduled to be restricted free agents.

There's the possibility that next season will bring a vastly different look with a new head coach -- and practically a new staff -- a new quarterback, receiving corps, offensive line, defensive line and relatively new secondary.

Whether or not Arizona's big three retires, the Cardinals will have an opportunity to wipe the slate clean and start from scratch in 2018 -- for however long it takes. And it should start now.