Late this summer, a New England Patriots official jokingly asserted that the franchise’s biggest problem during training camp was handling so many questions about whether they would go undefeated.

The defending champions were not only a favorite to repeat, they were on a different plane than the rest of the NFL, a franchise with its own gravitational pull. There was the Patriots, and there were the 31 teams chasing them.

A quarter of the way through the season, late summer seems like the distant past for the Patriots. In a span of four games, the central question of their season has shifted in unthinkable fashion. It is not, can they make it through the season without a loss? It is, can they make it through another week without embarrassing themselves?

Embarrassing — there is not another word for New England’s defense after four games. The Patriots are 2-2, tied with the New York Jets and a game behind the Buffalo Bills in the AFC East. They have yielded 32 points per game, more than any team in the NFL, and uniformly turned opposing quarterbacks into all-pros.  

The Patriots have faced Alex Smith, Drew Brees, Deshaun Watson and Cam Newton — two former MVPs, a rookie and a journeyman. All but one game came at home. Those quarterbacks have completed 99 of 142 passes for 1,341 yards, 11 touchdowns and three interceptions. Per game, that comes out to 25 of 36 for 335 yards, three touchdowns and a little less less than one interception. Through a quarter of a season, quarterbacks playing the Patriots have collectively put up the start of an all-time season.

The best simple measure of a quarterback’s performance might be yards per attempt. Against the Patriots this season, quarterbacks have posted 9.4 yards per attempt. That total that would have led the league every season since 2000 — no active quarterback has passed for 9.4 yards per attempt over a full season. Last year, MVP Matt Ryan punched up 9.3 yards per attempt. Aaron Rodgers’s career high is 9.2. Tom Brady’s is 8.6.

The Patriots have a defense incapable of going undefeated, defending a Super Bowl, or even winning a division. New England’s defense, in a word, stinks.

The hallmark of Coach Bill Belichick’s defenses is discipline. This season, the Patriots have busted for big plays with alarming frequency. In Week 1, they let Tyreek Hill sprint into an open pasture. On Sunday, Newton threw two touchdown passes to wide receivers who would not have been less open in pregame warm-ups. Mike Giardi of CSN New England identified big-ticket free agent corner agent cornerback Stephen Gilmore as the culprit.

“It’s frustrating when it’s communication, when it’s not ability,” Gilmore said. “I gotta get better at the communication part. It’s my fault on the communication.”

Poor teamwork has doomed the Patriots, perhaps, but ability matters, too. The Patriots appear to have a talent drain, a dearth of defensive playmakers, that somehow everybody missed, or assumed the genius of Belichick would redeem.

The Patriots lack an impact pass rusher. They lost Rob Ninkovich to retirement and tried to replace him with Kony Ealy and rookie Derek Rivers. Ealy was such a poor fit they waived him before Week 1, and Rivers suffered a season-ending knee injury in camp. They traded with the Seahawks for Cassius Marsh, who hasn’t worked, either. Trey Flowers and Deatrich Wise have shown glimpses, but no consistency.

The trades of Chandler Jones and Jamie Collins were both justified, but the Patriots have yet to make up for the loss of their athleticism and playmaking. Now, the Patriots are primed to make another trade. It’s unclear how much one deal can help a defense this bad.

Then again, the Patriots may not be as far off as their performance has shown. Aside from Ninkovich, the only two starters missing from last year’s Super Bowl are cornerback Logan Ryan (free agency) and linebacker Shea McClellin (injured reserve). Key defensive lineman Jabaal Sheard is also gone. But missing those four should not ruin a defense so severely. The Patriots have a little less talent, and their new players haven’t grasped Belichick’s system. Those two factors have created a defensive disaster.

The Patriots are lucky to be 2-2. Last week, Brady bailed out the defense with a last-minute touchdown drive, made possible only when Texans Coach Bill O’Brien kicked a field goal rather than trying for a game-clinching score on fourth and a foot.

The Patriots’ other problem is that the Bills might actually be good. Buffalo is 3-1 under first-year Coach Sean McDermott after upsetting the Falcons and becoming the first team to win in Atlanta since Week 13 last year. Two of the Bills’ wins have come against the Denver and Atlanta, a pair of 3-1 teams. Buffalo’s only loss came at Carolina, when it held the Panthers to nine points and saw a potential game-winning touchdown pass sail through wide receiver Zay Jones’s hands in the final seconds.

The Patriots have little time to address what is wrong. They will travel to Tampa Bay to face the Buccaneers on Thursday night. Belichick has a knack for solving thorny problems. It would be unwise to believe he can’t fix even this Patriots defense, be it through a personnel upgrade, adjustments or coaching points. The unit only has to be serviceable — Brady is again playing at a superhuman level.

Right now, the defense is only wasting another vintage Brady season. The Patriots have serious problems, bigger than anyone could have seen coming this summer.

>>> NFL players continued to grapple with how to approach the national anthem. In Baltimore, the anthem proved particularly controversial, as fans booed the Ravens when they knelt before the song, as Mark Maske and Dave Sheinin report.

I wonder: How many of the fans who booed players for kneeling during the song chanted “O!” — a tribute to the Orioles that is pervasive in the mid-Atlantic — during it? And if the fans are booing players for what they do before the anthem, as opposed to during it, then is their issue really “respect” for the flag? Or might it be football players, the majority of them African American, forcing them to confront uncomfortable issues?

>>> If not for the competition from McDermott, Sean McVay would be the easy early front-runner for coach of the year. The perennially mediocre-to-bad Rams are 3-1 after beating the Cowboys in Dallas, 35-30. Watching the Rams’ attempts to move the ball was drudgery for years. Under McVay, with largely the same players, the Rams have the most explosive offense in the NFL, having scored 35.5 points per game.

McVay’s best work has been unleashing third-year running back Todd Gurley. With Kansas City’s Kareem Hunt yet to play his fourth game, Gurley leads the NFL with 596 total yards. They key has been his usage as a receiver. In his first two seasons, Gurley had 2.8 targets per game. Through four weeks, the Rams have already thrown him 25 passes, or more than six per game. He’s caught 20 balls for 234 yards.

>>> Dalvin Cook looks like he’s done for the year with a torn ACL. Vikings Coach Mike Zimmer said Cook will go for an MRI to confirm the fears, but Zimmer already seemed resigned after the Vikings’ 14-7 loss to Detroit. “I told him he’s not the first great running back to have an ACL, if it is one, and come back pretty good,” Zimmer said. “Dalvin will have a great career.

It didn’t look good from the moment Cook, a rookie who entered the week third in the NFL in total yards, suffered an injury. Cook crumpled to the turf without being touched and immediately grabbed his left knee. The loss is devastating for the Vikings, who have already played without starting quarterback Sam Bradford for three games and don’t know when he’ll be back.

>>> You’d have to imagine Jared Cook is not a popular figure in the Oakland locker room. The Raiders, having trailed all afternoon, had a chance to stun the Broncos in the final minutes. Backup quarterback E.J. Manuel launched a pass down the seam and into the end zone for Cook. He was open, and the pass was on target. Rather than reach for the pass, Cook slid and shirked to avoid oncoming safety Darian Stewart. It was classic alligator arms, in one of the game’s biggest moments.

Rather than pull within two points, the Raiders settled for a field goal and trailed, 16-10. They had one more drive, but Manuel, desperate to score a touchdown rather than a field goal, heaved an interception. Cook’s lack of effort played a big role. It was especially unacceptable on a day the Raiders lost their starting quarterback to back spasms. It’s not clear how long Derek Carr will be out, but the Raiders, having lost two straight, are suddenly reeling.

>> The Jets are off to a surprisingly decent start after beating the Jaguars in overtime to move to 2-2. It would be a pleasant development had the Jets not devoted the 2017 season to acquiring a top 2018 draft pick, as Steve Politi writes.

>> Eagles fans filled the Chargers’ stadium, as Zach Berman writes. No matter how much the NFL expected the Chargers would struggle to attract fans in Los Angeles at first, the league never could have seen this coming. The Chargers had to cover up entire sections in a 27,000-seat soccer stadium. This is apathy unseen in the NFL and exceedingly rare in all big-time professional sports.

>> The Seahawks are searching for a running back — again. The end of their 46-18 victory was brutal, as impressive rookie Chris Carson suffered an apparent broken leg. They have to hope Eddie Lacy, who flashed on a few runs against the Colts, can assume a larger role. Rookie J.D. McKissic, a college receiver who caught a late touchdown pass from Russell Wilson after lining up outside, could also see more opportunities.

Read more on the NFL: