The biggest defensive star in the Lone Star state is out. That’s a void for the Houston Texans as big as, well, J.J. Watt’s persona.

In the mediocre AFC South, which Houston (2-1) leads, losing its best player could bring the defending division champion back to the field — as uninspiring as the Titans, Colts and Jaguars might be.

With the Texans coming off a no-show at New England, visiting Tennessee could be feeling pretty frisky about its chances Sunday.

“I’m very disappointed about that,” says Tennessee left tackle Taylor Lewan, who would have matched up a lot with Watt.

“I’ve said before if you want to be the best you’ve got to go against the best. I want to be the best left tackle in this league. I want the opportunity to go against all the best guys.”

Houston’s best on D for now will have to be Jadeveon Clowney and Whitney Mercilus.

“Jadeveon is playing awesome, Whitney,” Lewan adds. “So a lot of those guys, they’re going to give me all they’ve got. I’ve got to come with my ‘A’ game for sure.”

The Texans didn’t even bring their ‘D’ game to Foxborough in prime time . That 27-0 rout was more of an ‘F.’

And now, no J.J.

“When you have that kind of ability and that kind of playmaking it’s hard to replace with one guy,” Texans defensive coordinator Romeo Crennel notes. “So we’re going to ask all the guys on defense to pick it up, to put a little extra in it and see if we can gain some of those plays that J.J. used to make.”

The action began Thursday night with Cincinnati’s 22-7 home victory over Miami. A.J. Green had 10 catches for 173 yards and a touchdown, and the Bengals (3-1) were inspired by linebacker Vontaze Burfict’s return from a suspension.

During the first three quarters, Green had 166 yards on catches while Miami (1-3) had 152 total yards.

Burfict was suspended by the NFL for the first three games because of his illegal hits. The linebacker knocked down a pass and had three tackles.

Philadelphia (3-0) and Green Bay (2-1) have the first byes of the season.

Indianapolis (1-2) vs. Jacksonville (0-3) at London

The Jaguars make their annual trip to Wembley, and you have to wonder if Londoners would like to see the agreement with Jacksonville voided.

A loss in this early kickoff (9:30 a.m. EDT) could push Jags coach Gus Bradley closer to the edge of unemployment, what with higher expectations the team (and owner Shahid Khan) had entering the schedule.

Indianapolis has won six of the past seven in this series and has swept the Jaguars six times since becoming division foes in 2002. Frank Gore needs 88 yards rushing to pass Hall of Famer Marcus Allen (12,243), Colts rushing leader Edgerrin James (12,246), Hall of Famer Marshall Faulk (12,279) and Hall of Famer Jim Brown (12,312) to become No. 9 on the NFL career list.

Buffalo (1-2) at New England (3-0)

While most everyone obsesses over the QB situation in Foxborough, the fact is New England’s defense and running game have turned downright nasty. In their final game before Tom Brady returns, the Patriots get their, uh, patsies: Buffalo has lost eight of the past nine meetings.

Bills coach Rex Ryan gets more pleasure out of beating New England than any other opponent. If the Bills don’t find a passing game or clamp down on opposing passers, they’re unlikely to find success.

Denver (3-0) at Tampa Bay (1-2)

Most everyone already believed in the Von Miller-led Denver defense. Now it’s quarterback Trevor Siemian making folks turn their heads and shout praise. It’s a somewhat manufactured statistic, but still, Siemian became the first quarterback to throw for 300 yards and four touchdowns without an interception in his first road start, a win at Cincinnati.

Few teams have been as inconsistent as Tampa Bay, and facing that mighty D without your best running back, Doug Martin, is a major obstacle.

New York Giants (2-1) at Minnesota (3-0), Monday night

Two things the Giants swore they’d improved over 2015 was an ability to finish, and their overall defense. In last week’s loss to Washington, they fell short in both areas, and they were wildly undisciplined. Yes, Ben McAdoo’s Giants looked eerily similar to the final version of Tom Coughlin’s Giants.

Now they visit the Vikings, whose defense could give the Broncos a challenge as best in show. Minnesota doesn’t do much with the ball, but can stop just about anyone’s run or pass game.

Oakland (2-1) at Baltimore (3-0)

The Ravens are one of the NFL’s most pleasant surprises so far, in part because they’re relatively healthy after an epidemic of injuries in 2015. Their defense isn’t reminiscent of the Ray Lewis-led units, which doesn’t diminish its strong performances one bit.

Oakland’s work on D, meanwhile, has been as bad as anyone’s, and now the Raiders make their third long-distance trip in four weeks.

Kansas City (2-1) at Pittsburgh (2-1)

The Chiefs have lost all three visits to Heinz Field, last winning in the Steel City in 1986. If they can force eight turnovers again like they did against the Jets last weekend, that string of failure will end.

Coming off their worst loss in 17 years — that 34-3 phlop in Philly — at least the Steelers get back star running back Le’Veon Bell from a three-game suspension. But the running game was not a problem with DeAngelo Williams in for Bell.

“The two-back system would work here, but Bell is so dynamic when he plays the game I don’t want him to come off the field,” Williams says.

Carolina (1-2) at Atlanta (2-1)

With the other three members of the NFC South owning losing records, the Falcons could put themselves in great shape with a win over the division’s three-time defending champ. Also remember that Atlanta was 6-1 in 2015 and wound up 8-8.

Carolina, of course, was 15-1 a year ago and went to the Super Bowl. If the Panthers don’t protect Cam Newton better — he’s been sacked 12 times and hit plenty more — another such trip is unlikely. So is a win in the ATL.

Los Angeles (2-1) at Arizona (1-2)

Two teams that once represented St. Louis meet in an important early NFC West matchup. The Cardinals are tough at home, but the Rams beat them in Arizona last season, and after struggling for two games, their offense came alive in a win over Tampa Bay.

Arizona must beat the habit of starting slowly; the Cardinals haven’t scored in the first quarter yet. One good idea might be feeding star receiver Larry Fitzgerald. He has more receptions (153) and TDs (16) against the Rams than against any other franchise.

Seattle (2-1) at New York Jets (1-2)

Pete Carroll has a dilemma. Given the knee injury to Russell Wilson and the prospect of a bye next week, does the Seahawks coach sit his star quarterback and hope the running game and defense can sneak out of the Meadowlands with a win?

One of many things that could make Jets fans shudder is having to take on Seattle’s aggressive, physical defense a week after Ryan Fitzpatrick was intercepted six times by Kansas City.

“Seattle is still definitely up there when you think or talk about the defense in this league,” Fitzpatrick says. “They’ve probably been the standard for the longest, it’s a lot of the same guys, same scheme and it’s tough.”

Cleveland (0-3) at Washington (1-2)

So the Browns hire a substitute kicker when the regular guy goes down in practice. That replacement, Cody Parkey, misses three field goals, including a potential winner on the final play of regulation.

The Giants handed Washington a win last week, and the Redskins could be undermanned. They finished that contest minus two starters in the secondary and two on the offensive line, losing DB DeAngelo Hall and C Kory Lichtensteiger to injured reserve.

Dallas (2-1) at San Francisco (1-2)

A lot of silly questions arising in Big D about, uh, Big D — as in Dak. Rookie quarterback Dak Prescott has impressed while Tony Romo is sidelined, making Cowboys fans surmise the team is better off keeping him in the lineup when Romo is ready. Let’s see how Prescott fares against a solid defense, which he has yet to face.

And he won’t this week, either.

“I’ve been very impressed with him,” 49ers coach Chip Kelly says. “I think not only his athletic ability, but his poise and kind of sense of calm that he has about him in terms of playing the game. It doesn’t seem like it’s happening too fast for him and he’s done a great job in the first three games.”

New Orleans (0-3) at San Diego (1-2)

Despite some key injuries, the Chargers haven’t looked too bad. Now they get to face their former QB, record-setting Drew Brees.

Brees began his career in San Diego in 2001, left for Saints after 2005. This will be Brees’ first game at Qualcomm Stadium since suffering a right shoulder injury trying to recover his fumble in the 2005 finale. Brees became a free agent, signing with New Orleans, while Philip Rivers became the Chargers’ starter. Brees has led Saints to victories over San Diego in London in 2008 and New Orleans in 2012.

Detroit (1-2) at Chicago (0-3)

Once a great rivalry, there’s not much to recommend in this one.

Detroit has won six straight in the series, but could be short-handed with DL Ezekiel Ansah (left ankle) and LB DeAndre Levy (quadriceps) hobbling. Marvin Jones, the NFL’s leading receiver, had a career-high 205 yards and two TDs last week in a loss to Green Bay.

Bears QB Jay Cutler (sprained right thumb) sat out last week’s loss to Dallas.