The Texans have never admitted it publicly, but the framework to trade outside linebacker Jadeveon Clowney began to take shape before the 2018 season when they were unable to sign him to a multiyear contract extension.

The decision to trade Clowney turned out to be instrumental in the acquisition of Miami left tackle Laremy Tunsil even though, ultimately, Clowney was shipped to Seattle rather than the Dolphins. But the groundwork to get Tunsil to protect quarterback Deshaun Watson's blind side had been laid.

From the time the Texans finalized their plan to trade Clowney and acquire other players to bolster the roster, team chairman Cal McNair had coach Bill O'Brien as his point man doing most of the negotiations and closing the deals.

Since McNair fired former general manager Brian Gaine in early June and gave O'Brien power over personnel, the Texans have been more aggressive in their pursuit of players.

O'Brien makes the final decision on players and answers to McNair. To assist in the process, O'Brien relied on a team of executive vice president of team development Jack Easterby, senior vice president of football administration Chris Olsen, director of player personnel Matt Bazirgan, director of football information systems Russell Joyner, director of pro personnel Rob Kisiel, assistant director of pro personnel C.J. Leak and director of college scouting James Liipfert.

According to multiple people familiar with what transpired, the genesis of the Clowney trade was a lack of progress in negotiations for more than a year. The two sides were far apart and remained far apart.

Extensions signed during the 2018 offseason by Chicago outside linebacker Khalil Mack (six years, $141 million, $90 million guaranteed, $23.5 million average) and Los Angeles Rams defensive tackle Aaron Donald (six years, $135 million, $86.8 million guaranteed, $22.5 million average) complicated negotiations with other top pass rushers who saw an opportunity to get more lucrative contracts.

Dallas defensive end DeMarcus Lawrence and Seattle defensive end Frank Clark, who was traded to Kansas City, were able to take advantage of the elevated pay scale for elite pass rushers. Clowney was not.

Clowney's agent, Bus Cook, visited training camp in West Virginia last year to talk with Olsen, who oversees the salary cap and contract negotiations, but left without a deal.

When last season began, trading Clowney — or making another run at trying to extend him — was placed on the back burner and didn't reignite until before this year's draft, according to those familiar with the situation. Ultimately, the Clowney saga ended Aug. 31 when O'Brien dealt him to the Seahawks.

That same day, O'Brien acquired Tunsil, receiver Kenny Stills and a fourth-round draft choice from Miami. He sent the Dolphins two first-round draft choices, a second-round selection, offensive tackle Julién Davenport and cornerback Johnson Bademosi.

The Texans refused to pay Clowney like an elite pass rusher. Coupled with their desperation to find a franchise left tackle to replace Duane Brown, who was traded to Seattle during the 2017 season because of a contract dispute, they formulated a plan to swap Clowney for Tunsil.

When the Texans placed the non-exclusive franchise tag on Clowney in early March, former general manager Brian Gaine said they would continue to try to sign him, but there were no substantive negotiations after that.

The franchise tag meant another team could sign Clowney, and if the Texans didn't match, they would have received two first-round picks. No team was interested in him at that price tag.

Before this year's draft, the Texans tried to trade Clowney. They contacted more than 10 teams. They zeroed in on Kansas City, but the Chiefs acquired Clark from the Seahawks. They surrendered first- and second-round draft choices for Clark and a third-round pick.

Clark signed a new contract with the Chiefs (five years, $104 million, $62.3 million guaranteed, $20.8 million average).

Lawrence, meanwhile, re-signed with the Cowboys (five years, $105 million, $65 million guaranteed, $21 million average).

Clowney wanted a contract slightly more than Clark and Lawrence, but the Texans had decided they weren't going to pay him $100 million, no matter how many players signed contracts in that stratosphere.

Seattle general manager John Schneider disclosed last week he first spoke to the Texans about Clowney before the draft. They wanted too much. He still had Clark on the roster. After trading Clark to the Chiefs, Schneider remained patient and wouldn't bite on a Clowney deal unless the price was reduced significantly.

After McNair fired Gaine in early June, O'Brien became the general manager without the title and was determined to be more aggressive in the trade market than Gaine had been.

O'Brien and his offensive staff had coveted Tunsil for two months and wanted him in a deal that included Clowney and draft choices.

Clowey had known for weeks he was going to be traded when he signed the tender. Once the July 15 deadline passed for franchise players to sign multiyear contracts until 2020, Clowney was holding the cards. He could veto any trade by not signing his franchise-tag tender.

The Texans offered to trade Clowney to Miami for Tunsil and multiple high draft picks. The Dolphins wanted Clowney, but he didn't want the Dolphins even though he had worked out in Miami during the offseason when he refused to report to the Texans because he was unhappy about not getting a long-term deal.

According to two people close to Clowney, he didn't want to play at Miami for two reasons: the Dolphins are rebuilding, and he didn't want to play for a team that wasn't a playoff contender.

Clowney also didn't want to play for new Dolphins coach Brian Flores, who left New England for Miami. Clowney wasn't interested in playing for another Bill Belichick disciple after spending five years with O'Brien.

The Texans gave the Dolphins permission to meet with Clowney, but Flores couldn't change his mind.

Over the past three years, O'Brien always said good things when asked about Clowney. But what he didn't say was revealing.

Usually, when O'Brien is asked about one of his players, he talks about what great team players they are and how hard they work. He never described Clowney that way. Several close to O'Brien said he didn't believe Clowney was part of the team culture he believes is conducive to winning.

Cook knew his client had three options: Sit out regular-season games and lose $939,000 a week, wait until teams were no longer interested in a trade and play one more season for the Texans or sign the tender and be traded.

Cook reiterated to the Texans that Clowney wasn't going to Miami. Cook told them to target Seattle or Philadelphia, two playoff contenders that play 4-3 schemes, which would allow Clowney to return to right defensive end, his natural position.

Brown, the Texans' first-round pick in 2008 who signed a multiyear contract with Seattle last year, was contacted by Clowney a month before the trade.

Brown told Seattle reporters he said good things about coach Pete Carroll, the organization, the weather and the city. Clowney expressed interest in finding a way to get to the Seahawks as Brown had done in 2017 when former general manager Rick Smith traded him for second- and third-round draft choices.

The Eagles came up with an offer, but it wasn't as good as Seattle made. The Seahawks offered a third-round draft choice and two defensive ends, Barkevious Mingo and Jacob Martin, who'll be moved to outside linebacker by the Texans.

For more than a year, agents tried to entice Clowney to leave Cook, claiming they could have gotten him the kind of contract he wanted. Finally, Clowney fired Cook but didn't sign with a new agent. A week later, he rehired Cook, and the trade was completed.

O'Brien got McNair to chip in $7 million of Clowney's $15.967 million salary this season.

Somehow, Cook convinced the Seahawks to promise not to designate Clowney as the franchise player again in 2020. That means Clowney could be one and done in Seattle. If he stays healthy and plays well, either the Seahawks or another team should reward him with a contract that'll pay him north of $100 million.

Meanwhile, at the same time the Clowney deal was going down, O'Brien continued to pursue Tunsil.

With Clowney out of the picture, O'Brien sweetened the pot for Miami, offering two No. 1 picks and a second-round selection while also asking for Stills to be included.

As a coach, O'Brien wants to win now. As a de facto general manager, he'll worry about the 2020 and 2021 drafts later.

The Texans' thinking was this, according to three people close to the situation: Tunsil would step in at left tackle and help protect Watson for years. Both will get extensions next year. Stills brings speed, durability, a 16-yard average per catch in his career and 21 touchdowns over the last three years.

The Texans believe, like this year, they'll be picking low in the first and second rounds. They can spend more in free agency to make up for the loss of draft choices. Or they could possibly trade back into the first and second rounds.

With O'Brien being in charge now, it's clear by his actions on cutdown day a new era has been ushered in when it comes to player acquisitions. If Aug. 31 was an indication of how O'Brien is going to operate, fans could be in for a wild ride during the next free agency period and the 2020 draft.