Adam Schefter explains that the Texans have not offered Jadeveon Clowney a major deal, so he will likely miss training camp. (0:47)

HOUSTON -- Last year, the Houston Texans had two of the top pass-rushers in the NFL in J.J. Watt and Jadeveon Clowney. By not reaching a long-term extension by the franchise tag deadline on Monday, the Texans risk losing Clowney -- the first overall pick in the 2014 draft -- at the end of the season instead of building around the core talent they have right now.

The Texans placed the non-exclusive franchise tag, which is worth $15.967 million for the 2019 season, on Clowney in March and the outside linebacker/defensive end did not attend any of the Texans’ spring workouts, including the mandatory veterans minicamp.

While the Texans could of course still sign Clowney to a new contract after the 2019 season -- or tag him for the second year in a row -- they likely wouldn’t match what the pass-rusher would get on the open market.

The Raiders learned last season that you can’t let a player of that caliber go when they traded outside linebacker Khalil Mack to the Bears for two first-round picks. Mack gave a huge boost to the Bears defense (12.5 sacks, 18 QB hits), while Oakland coach Jon Gruden said later in the season that his team was in need of a pass-rusher.

There are few teams that have a pair of defensive linemen like the Texans do with Watt and Clowney. Last season, Houston ranked 12th in total defense but third against the run. The 3.4 rushing yards allowed per attempt was an NFL low due to the performances of Watt and Clowney.

After not agreeing to an extension with the Texans, Jadeveon Clowney is likely to miss most or all of training camp. Chris Szagola/AP Photo

Last season, Clowney was named to his third straight Pro Bowl, and finished the regular season with 47 tackles, nine sacks, a forced fumble and a fumble recovery. According to NFL NextGen, the Texans' defender had a Pass-Block Win Rate of 35% -- second-best among qualifying defensive ends/linebackers. He also had 16 tackles for loss, which tied for ninth in the NFL last season, and now has 53 tackles for loss over the past three seasons, third in the league.

According to Pro Football Focus, Clowney had the best season of his career “by far” in 2018. His overall grade of 89.5 was tied for seventh best among edge defenders. He had 28 run stops on 283 run-defense snaps, the 10th-best run-stop percentage at his position.

While Clowney is not expected to report to training camp on July 24 with the rest of his teammates because he did not get a new contract, it’s unlikely his holdout will continue into the regular season, where he would miss out on game checks worth more than $1 million per game.

Where Clowney Would Rank Among Top DEs Player/Team Average Annual Salary 1. DeMarcus Lawrence, DAL $21M 2. Frank Clark, KC $21.8M 3. Trey Flowers, DET $18M 4. Cameron Jordan, NO $17.5M 5. Dee Ford, SF $17.1M 10. Jadeveon Clowney, HOU $15.9M Source: Spotrac.com

After he missed most of OTAs and training camp a year ago, it took Clowney a few weeks to get back into rhythm. He didn’t play until the third preseason game against the Rams and played just three series.

If Clowney holds out during training camp, he’ll be in the same situation. Yes, he has been working out by himself and should be in football shape whenever he does report, but missing camp will only slow his production, at least early on.

The Texans have Watt, who put up a performance in 2019 (16 sacks, 25 QB hits, 18 tackles for loss) rivaling some of his Defensive Player of the Year seasons in 2012, 2014 and 2015 (combined 48.5 sacks), but Watt is better when Clowney is on the field. The players make each other better, and each often takes on double-teams so the other player can get to the quarterback.

Clowney deserves a new contract. He won’t get Mack money or Aaron Donald money, but he should get paid. It is tricky because the Texans are paying Watt $15 million a year, but they have the financial flexibility (nearly $41 million in cap space according to ESPN's Roster Management) to make it work, even if they do have to pay Deshaun Watson in a year or two.

During OTAs, coach Bill O’Brien said he has “every belief and trust that JD’s [Clowney] working on his own and getting ready for whenever he does decide to show up.

“JD's played good football for us,” O’Brien said. “He knows what it takes to be ready for training camp and things like that.”

Clowney is a difference-maker on the Texans’ defense, and the team will be worse off if he is not back on the field for Houston either this season or next.