FOXBOROUGH, Mass. — A sore back isn’t all Mac Jones is dealing with heading into the Steelers game.

The Patriots’ quarterback missed Thursday’s practice with an illness, according to the team. The NFL Network reports it’s not COVID-19 related, “Jones just had an upset stomach so they decided to give him the day off.”

Jones has also been dealing with a back injury that required X-rays after last week’s loss to the Dolphins. On Wednesday he was listed as a full participant at practice, and said he expected to play — but this was before the new illness hit.

The Patriots opened practice with a series of drills that included one designed to keep fumbles from bouncing out of bounds. So yes, Bill Belichick is as focused on the little things as ever.

Veteran backup Brian Hoyer led the first-team offense in Thursday’s practice, while fourth-round rookie Bailey Zappe directed the scout team. The Patriots typically run through the third-down portion of their game plan on Thursdays. On Wednesday, Jones and the offense executed the first and second-down plays they want to execute in Pittsburgh. Friday practices are typically light and always non-padded.

Linebacker Ja’Whaun Bentley, who missed Wednesday’s practice with a hurt toe, appeared to move without limitation during warm-ups on Thursday. On the field, the Patriots were down practice-squad linebacker Cameron McGrone, defensive lineman LaBryan Ray and offensive lineman Bill Murray. McGrone and Ray were also absent Wednesday.

STEELERS: The Pittsburgh Steelers placed star outside linebacker T.J. Watt on injured reserve, meaning he will miss a minimum of four games while recovering from a left pectoral injury.

The Steelers already had ruled Watt out for Sunday’s visit by New England. The NFL’s reigning defensive player of the year sustained the injury in the fourth quarter of last week’s overtime victory against Cincinnati.

Pittsburgh Coach Mike Tomlin said earlier in the week that Watt’s injury wasn’t as bad as initially feared. Watt received multiple opinions during the week and does not need surgery, which opened the door for him to return at some point this season.

The Steelers filled Watt’s spot on the 53-man roster by signing David Anenih off Tennessee’s practice squad. Anenih spent training camp with the Titans after being signed as an undrafted rookie free agent out of Houston. Tennessee waived Anenih before signing him to the practice squad.

Anenih collected 20 1/2 sacks in four seasons with the Cougars.

SEAHAWKS: Confirming the worst fears the moment the injury happened Monday night, safety Jamal Adams is expected to miss the rest of the season after suffering a knee/quad injury in Seattle’s 17-16 win over Denver that will require surgery.

The Seahawks officially placed Adams on injured reserve after it was revealed he would have surgery soon to repair a torn quad tendon, which is expected to sideline him for the rest of the season. The exact details of when and where he will have surgery are still being sorted out.

Adams was injured early in the second quarter on a play when he blitzed Russell Wilson.

Adams was looked at in the medical tent before being carted off the sideline, and Coach Pete Carroll after the game called it a “serious injury.”

RAVENS: Four days after Week 1 starter Kyle Fuller suffered a season-ending knee injury, projected Week 2 starters Marlon Humphrey (groin) and Brandon Stephens (quadriceps) were limited and missing at practice, respectively.

The Ravens could get some help Sunday against Miami with the activation of Marcus Peters (knee), a full participant in practice Thursday for the first time this season.