Patriots defensive tackle Christian Barmore has been diagnosed with blood clots and there is no timetable for his return. Bryan Woolston/Associated Press

FOXBORO, Mass. — Fresh off a career year and big contract extension, Christian Barmore was supposed to be a foundational piece of the first Patriots defense of the Jerod Mayo era.

Now it’s unclear whether Barmore will see the field at all.

On Sunday, the Patriots announced that Barmore, their 25-year-old shop-wrecking defensive tackle, will be out indefinitely after being diagnosed with blood clots.

Mayo opened his Monday news conference by thanking the Patriots’ medical staff, led by head trainer Jim Whalen, and doctors at Massachusetts General Hospital for their treatment of Barmore.

“I just want to thank the medical professionals in-house and also Mass General as far as the care for Barmore,” Mayo said before New England’s fifth training camp practice. “Obviously it’s an unfortunate thing, but for me, it’s not even about football. When you talk about things like that, it’s about the man. He’s getting tremendous care and I’m anticipating him coming back.”

When?

That was unknown as of Monday afternoon. Mayo said Barmore was out of the hospital, “in good spirits” and joined at home by his mother, but the Patriots’ head coach had “no timetable” for his return to the field.

“When he’s ready to go, we’ll be here waiting for him,” Mayo said. “… He just wants to play football, but in understanding the seriousness of this, he needs to get healthy, and we’ll be praying for him.”

The Patriots dealt with a similar situation in 2019, after doctors found blood clots in the lungs of center David Andrews during the preseason. Andrews had to take blood thinners as part of his recovery and missed the entire season as a result.

It’s too early to say whether Barmore’s condition will require the same season-long layoff, but it would not be surprising if he’s forced to miss significant time. That would be a massive loss for a defense that has elite potential after returning nearly all of its top contributors from 2023.

Barmore led the Patriots in sacks (8.5) and quarterback hits (16) last season, and ranked second in tackles for loss (13), setting career highs in all three categories while playing in every game. Asked how New England can replace him while he heals, Mayo replied: “That’s a great question. We’ll see.”

“A guy like Barmore, as disruptive as he is, it’s kind of hard to get that same production,” he said. “But look, other guys have to step up and treat it like a normal injury, even though it’s not a normal injury, and next man up.”

Players who could take on larger roles in Barmore’s absence include Daniel Ekuale and veteran newcomer Armon Watts, who came from Pittsburgh in free agency.

The 6-foot-5, 307-pound Watts said Monday that he had his most productive season after starter Michael Pierce suffered an injury for Minnesota in 2021. Pushed into a more prominent role, Watts notched five sacks and 10 quarterback hits, surpassing his totals from his other four pro seasons combined.

Jeremiah Pharms, Trysten Hill, Sam Roberts and the newly signed Josiah Bronson are other defensive tackles competing for roster spots in the Patriots’ camp.

IT’S NOT ALWAYS going to be pretty for rookie quarterback Drake Maye.

And on Monday, in the first padded practice of his NFL career, it was downright ugly at times.

Maye completed just three passes on 11 attempts in 19 snaps. He was sacked twice and threw an interception in seven-on-seven drills.

Meanwhile, current Patriots starter Jacoby Brissett further solidified his standing by going 13 of 16 with two deep completions to wide receiver Tyquan Thornton and one to rookie wideout Javon Baker.

DURING PRACTICE, attention was focused on the drama off the field surrounding outside linebacker Matthew Judon and defensive tackle Davon Godchaux.

It was hard not to be distracted by off-field matters when the Patriots took the field. Drew Rosenhaus, the agent who represents five New England players, including Godchaux, was in attendance with his brother, Jason, in the friends and family area.

Godchaux, who’s entering the final year of his contract, sounded off last week, saying, “I just want some respect,” as he seeks guaranteed money.

The Rosenhaus brothers spoke to Matt Groh, the Patriots’ director of player personnel, before Robyn Glaser, the team’s executive vice president, football business and senior advisor to the head coach, joined the discussion.

After the chat, Jason Rosenhaus was led to the facility by a Patriots scout.

Judon, who said last week that he doesn’t want to play on his current contract, entered practice in sweats and wearing a baseball cap, and ran a lap around the field, including in front of the media, before sitting on practice mats while the remainder of the team did stretching.

Judon had a lengthy discussion with Coach Jerod Mayo while the rest of the team participated in special teams and individual drills before leaving practice.

Judon returned in a T-shirt, hat, sweats and slide sandals, and walked over to Groh and Eliot Wolf, the team’s executive vice president of player personnel, on the sideline. Judon had his back turned to the media but appeared to be animated in his conversation with the two team personnel executives before walking back across the practice field and down the stairs toward the team facility.

The Patriots borrowed money from Judon’s 2024 salary to give him a raise last offseason.

Godchaux wore a jersey, shoulder pads and a helmet to the padded practice but did not appear to be in leg pads. He participated in practice, unlike Judon. Judon had, up to this point, been a full participant in practice, so it’s difficult to categorize him as a holdout.