FOXBOROUGH – The New England Patriots fell 33-14 to the Chicago Bears on Monday in what might have been one of the worst losses in Bill Belichick's 23-year tenure as the team's head coach.

Here are five takeaways from the Week 7 loss.

1. Patriots have a quarterback crisis

A week ago, it looked like the Patriots had something in Bailey Zappe: a dependable backup they could call should anything happen to Mac Jones. The second-year quarterback made his return on Monday night after missing the last three games due to injury, and received a quick yank. New England went three-and-out on its opening two possessions before Jones threw an interception on a very questionable pass.

Bailey Zappe's opening two drives certainly seemed like he shut the door on any quarterback questions for the rest of the season. He completed a pair of deep passes, one of which was a 25-yard touchdown to Jakobi Myers, to lead the Patriots to two touchdowns on his opening two drives.

But it went all downhill from there for the Patriots' rookie quarterback. He was credited for a fumble on a weird zone handoff for Meyers late in the first half. He failed to move the ball in the second half as the Patriots went three-and-out on their first two drives. On their next two possessions, Zappe threw an interception, with one being tipped at the line of scrimmage and one being a very weak throw on a fourth-and-2 throw to Tyquan Thornton. In addition, Zappe's small frame for a quarterback (he's listed at 6-foot-1 but might be smaller than that) became noticeable when he threw four passes that were tipped at the line of scrimmage in the second half alone.

So, the Patriots have possibly ruined the confidence of their second-year quarterback, who led them to the playoffs as a rookie, while their fourth-round rookie quarterback got exposed. The decision to make the switch was apparently preplanned as Bill Belichick told ESPN that he would play both quarterbacks prior to the game and confirmed that following the loss. Even though Belichick said Jones' benching wasn't performance-related, it certainly wasn't the best look to pull him as quick as possible with fans in the stadium booing Jones and chanting for Zappe.

The Patriots can certainly navigate their way out of this situation. There are still 10 games left in the season, enough time to rebound from their questionable decision on Monday night. They created more questions though than they needed, and they must figure out the answers to those questions immediately.

2. The run defense is back to square one

After two strong performances against the Detroit Lions and Cleveland Browns, the Patriots' run defense looked the worst it has been all season. They gave up 243 yards to the Bears, with Justin Fields and their two lead running backs doing damage. Fields rushed for a game-high 82 yards on 14 carries, while David Montgomery and Khalil Herbert each had 62 yards.

There appeared to be a mixture of reasons for the Patriots' poor play against the Bears' ground game. Safety Kyle Dugger, who's arguably the Patriots' top tackler, went down in the first half due to injury and didn't return. The other reason, though, was that the Patriots played a lot of zone coverage and went heavy on having defensive backs out on the field to help match Fields' speed. The combination allowed Fields to break loose whenever the pocket collapsed while also giving the Bears' running backs golden opportunities to pick up yards whenever they ran.

Sure, the injury to Dugger and defensive tackle Christian Barmore's absence didn't help, but it's clear that the Patriots lack the personnel at linebacker to play well-rounded defensively on a week-to-week basis.

3. The offensive line was disappointing

Just like the Patriots' rush defense, the offensive line had a bad game on Monday after playing strongly in recent weeks. And it was noticeable from the get-go.

On Jones' first dropback, starting left tackle Trent Brown was called for holding, his first of four penalties on the night. On third down of the first drive, Cole Strange got beat right away, forcing Jones to scramble on a third-and-long.

On Jones' first dropback on the second drive, right guard Michael Onwenu got beat right away at the snap, forcing Jones to scramble left before getting sacked quickly. Brown's false start later in the drive put the Patriots in another third-and-long situation, leaving the Patriots' offense dead to rights.

The offensive line didn't play much better with Zappe in. Marcus Cannon, who replaced an injured Isaiah Wynn at right tackle on Monday, allowed three pressures. The run game never really got going against one of the league's worst run defenses either as Damien Harris and Rhamondre Stevenson combined for just 47 yards on 14 carries.

4. At least Matthew Judon played well

The Patriots' best player came to play on Monday night. He played the mobile Fields well, chasing him well out of a pocket for a sack in the first half. He read Fields well on a run-pass option that resulted in another sack. He also chased down Fields for a third time in the first half when the quarterback scrambled while looking for a play downfield.

Not only did Judon finish with 2.5 sacks, he also tipped a Fields pass at the line of scrimmage that resulted in an interception for Myles Bryant.

Judon continues to be a force each week. He has already recorded 8.5 sacks this season, the most in the league, while recording a sack in six of the Patriots' first seven games.

5. More questions linger for the Patriots

Monday night was supposed to be a blowout win for New England. It was at home against a Chicago team widely viewed as one of the worst in the league with a quarterback who has failed to prove much in his first two seasons in the league.

Instead, the 8.5-point favorite to win Monday's game looked like they were the team that was one of the worst in the league with major issues at quarterback. The Patriots struggled in all facets of the game, and more importantly, created a quarterback crisis that could've been avoided. They now sit at 3-4 with a huge game against the 5-2 New York Jets coming up. A loss could ultimately sink them for the remainder of the season, a thought that would've been laughed off ahead of Monday's game.

A win against the Jets could get the Patriots back on the right track, but it's going to take several games for them to get out of the hole they created in Week 7.