"We're ticked off," Ravens quarterback Lamar Jackson said. "Don't nobody like losing ... especially when we have a lot of talent on our team. We've just got to regroup."
The Ravens (6-3) have lost more games than they did all of last season, when they went 14-2 and finished as the top seed in the AFC. Baltimore is three games back of the AFC North-leading Pittsburgh Steelers (9-0) and holds the No. 7 and final playoff spot in the AFC.
On a night of heavy rain at Gillette Stadium, the Ravens scored their fewest points since Jackson took over as the starting quarterback. They had set an NFL record by scoring 20 or more points in 31 straight games.
This loss came after Jackson said last week on the "Rich Eisen Show" that defenders were calling out the Ravens' plays.
Asked if Patriots defenders were telegraphing Baltimore's plays, Jackson said, "No, no, we were doing a great job. Coach [offensive coordinator Greg Roman] was dialing it up. We've just got to finish drives."
Injuries are starting to mount for Baltimore. Two weeks after All-Pro left tackle Ronnie Stanley suffered a season-ending ankle injury, tight end Nick Boyle was carted off the field Sunday with a season-ending knee injury.
"Those guys are huge," Jackson said. "They're great players for us. We need them. They're starters for a reason. We don't like to see none of our guys go down."
By the end of the game, the Ravens were without four starters on defense because of injuries: defensive end Calais Campbell (calf), nose tackle Brandon Williams (ankle), cornerback Jimmy Smith (ankle) and inside linebacker L.J. Fort (finger).
Baltimore's next two games are home against Tennessee (6-3) and at undefeated Pittsburgh.
"We're just going to stick together. We're going to build," Jackson said. "It's one team, one goal. We're good."