Julian Edelman caught 10 passes for 100 yards in the Patriots’ victory over the Chiefs. (Maddie Meyer/Getty Images)

The renewed New England Patriots offense hurled its usual blizzard of challenges Sunday evening at the robust Kansas City Chiefs defense. The tabloid-looks quarterback, Tom Brady, who operates with unmitigated precision and contained rage. The tight end, Rob Gronkowski, who looks like a science experiment. They vacuum so much attention in any game that it’s possible to overlook the key to it all, Julian Edelman, the sawed-off slot receiver who makes defensive backs look like they’re trying to wrangle a greased calf.

The Patriots offense became whole Sunday in their 27-20 divisional round playoff victory at Gillette Stadium for no singular reason. None was more crucial, however, than the return of Edelman from a foot injury. In his first game since Nov. 15, Edelman showed rust and dropped four passes, three of them early on. But he caught 10 balls for 100 yards, ran it once for another 11 and served as the linchpin Saturday. At their full force, the Patriots are nearly unbeatable, and the man who makes them go is Edelman.

It sounds preposterous to give Edelman such a designation considering he plays on the same team as Brady and Gronkowski. It’s not. The Patriots managed injuries all season on offense, including having to start 13 different five-man combinations on the offensive line. There was no difference starker for them than playing with Edelman or without him.

With Edelman in the lineup, the Patriots went 9-0 and scored 33.6 points per game. Brady averaged 338 yards and threw 24 touchdown passes against three interceptions. Edelman missed the season’s final seven games, and the Patriots averaged 23.1 points and went 3-4. Brady’s numbers? Two-hundred-forty-seven yards per game, 12 touchdowns and four picks.

Those numbers made this postgame revelation from New England reporters somewhat terrifying for the Patriots: As reporters marched into the Patriots’ locker room, Edelman limped past on his way to the X-ray room inside Gillette Stadium. But Edelman showed no sign of injury on the field, and it is common for players to get immediate checks on still-healing injuries. He returned the locker room quickly, and told reporters he felt “comfortable” planting on his foot.

At 5-foot-10, Edelman cannot match Gronkowski as an imposing force. At receiver, he cannot conduct the game like Brady. His special skill, and his relentless application of it, is merely the engine of the Patriots’ radiant offense. Edelman, his legs pumping like the needles of a sewing machine, could shed a cornerback in a phone booth. The Patriots line him up in a position that allows him to cut either inside or out, and they can count on him for five or seven yards any time they need it.

Brady’s exactitude and Edelman’s acute routes create an unstoppable combination. Edelman functions in the Patriots offense as an evolutionary version of a workhorse running back. He keeps the chains moving with limited risk. Brady has thrown to him 104 times this season. Only two of those passes have been intercepted.

Edelman has evolved into a player capable of more than option routes in the middle of the field. Sunday, Edelman ran a wheel route up the sideline, and Brady fired a back-shoulder pass behind. The pass came out low, but Edelman twisted, ducked and plucked the ball from the tip of the turf. Sean Smith had covered him perfectly. It didn’t matter.

The Patriots remained diminished at offensive line, and Edelman’s presence serves as tonic for that problem. He gets open so quickly, and so reliably, that Brady can use him as a safety valve. Brady was sacked twice per game during Edelman’s absence this season. Sunday, against the defense that finished fourth in the NFL in sacks, Brady’s jersey stayed clean.

On the Patriots’ final meaningful play, with a minute remaining, Brady dropped to pass and rifled a pass to Gronkowski. It deflected off his arm and floated in the air for a dangerous half second. Edelman, in just the right place, snared it and lunged forward. Potential disaster turned into a game-sealing first down.

Edelman would not be able to make any offense great alone. But then neither could Brady and Gronkowski, who led a largely mediocre offense for two months. The Patriots are two wins away from a fifth Super Bowl title. It would be a defense of last season’s championship, when Brady was named MVP and Edelman caught the game-winning touchdown.