FOXBOROUGH, Mass. -- The New England Patriots' offense sputtered in a surprising 18-12 loss to the Denver Broncos at Gillette Stadium on Sunday, putting the franchise in an unfamiliar spot.

The Patriots (2-3) haven't been under .500 through the fifth game or later since they were 3-4 in 2002. That was the last season the Patriots did not win 10-plus games.

The Buffalo Bills, who host the Kansas City Chiefs on Monday, lead the AFC East with a 4-1 record.

The Patriots had hardly practiced over the past two weeks, as their facility was shut down multiple times because of COVID-19. The lone full-pads practice had been Thursday, which was the first day quarterback Cam Newton returned after testing positive for COVID-19 on Oct. 2.

Sunday's Broncos-Patriots game had originally been scheduled for Week 5, but was postponed after Patriots starting defensive tackle Byron Cowart had tested positive for COVID-19 two days before kickoff.

The Patriots then closed their facility for three days before opening up for conditioning work last Wednesday. They then held their lone practice Thursday before abruptly canceling their Friday practice after reserve offensive lineman James Ferentz tested positive for COVID-19.

The Patriots currently have five players on the reserve COVID-19 list: Cowart, Ferentz, running back Sony Michel, starting right guard Shaq Mason and reserve defensive end Derek Rivers.

During Sunday's loss to the Broncos, they lost starting right tackle Jermaine Eluemunor (ankle) and reserve defensive tackle Adam Butler (elbow) to injuries in the first half.

After falling behind 18-3, they made a charge in the fourth quarter, but it was too late.

The game marked the first time the Patriots didn't score a first-half touchdown at home since Week 4 of the 2016 season -- a 16-0 loss to Buffalo in a game Jacoby Brissett started with Tom Brady serving a four-game NFL suspension.

Sunday's loss also marked the first time that a Belichick-coached Patriots team didn't win when not allowing a touchdown. Including the playoffs, they had been 39-0 in those games.