ENGLEWOOD, Colo. -- By the time the Broncos and Patriots kick off Sunday, 56 days will have passed since their Week 12 meeting. It only seems longer than that.
Consider what was different for the Broncos' 34-31 overtime loss than it will be at Sports Authority Field at Mile High:
... The presence of defensive lineman Derek Wolfe, defensive tackle Kevin Vickerson, cornerback Chris Harris, Jr. and linebacker Von Miller. All are on injured reserve, and Wolfe and Vickerson didn't play another snap in the 2013 season after that frigid night in Foxborough;
... The absence of tight end Julius Thomas, who injured his knee the week before. He would miss two games before returning Dec. 8 against the Tennessee Titans;
... The absence of cornerback Champ Bailey, who was missing his fourth consecutive game and ninth of the season to that point. He returned the following week, missed two more games, but has played ever since;
... The presence of Patriots tight end Rob Gronkowski, who was in the middle of his return to the lineup after missing the first six games of the season because of offseason surgeries;
... The presence of linebacker Brandon Spikes, who played 67 defensive snaps for the Patriots that night but was placed on injured reserve last week. Rookie Jamie Collins -- "a guy we liked in the draft," said head coach John Fox -- has been part of the solution for replacing Spikes;
... And finally, the Broncos' head coach, since Jack Del Rio was in the third week of his four-game interim stint while John Fox recuperated from aortic valve replacement surgery.
All this explains why this AFC Championship duel is rematch, and not a replay.
With Gronkowski in the lineup, the Patriots averaged 6.68 yards per pass play and 5.69 yards per snap; without him, they have averaged 5.80 yards per pass play and 5.26 yards a snap.
However, they have seen their per-carry average increase from 4.27 with him to 4.56 without him, which is largely due to the recent form of LeGarrette Blount and the Patriots' tendency to send him through the middle to exploit defenses spread out to monitor their slot and outside receiving threats.
Most promising for the Patriots is the fact that offensive points per 60 minutes are only slightly down without Gronkowski; they averaged 27.16 points per 60 minutes with him and 26.57 without him.
"I don't think they changed. I just think they have more success (running)," said defensive tackle Terrance Knighton.
The Patriots' strengths are a bit different now, but the offense is nearly as efficient.
"They've had a lot of things happen to their football team, just like we have had a lot of things happen to our football team, and I think that they've done a tremendous job kind of reinventing as far as the run game," said Fox. "They've lost pass-catching tight ends and have incorporated some guys that are doing a really, really good job in the run game.
"Bill (Belichick) has adjusted -- that's why he's going to be in the Hall of Fame."
But so has Fox and his staff. The offensive adjustments the Broncos made this year were significant, especially after losing Ryan Clady in Week 2 to a Lisfranc injury. They lost Thomas for two games, right tackle Orlando Franklin for one and wide receiver Wes Welker for three, but never scored fewer than 20 points, making the 2013 Broncos the first team in club history and the 12th in NFL history to score at least 20 points in every regular-season game.
But the defensive switches were far more profound. Nine different first-teamers missed a combined 61 games over the 17 games to date. That began with middle linebacker Stewart Bradley, who injured his wrist after starting in a preseason loss at Seattle and was lost for the year. Bradley was the first of six defensive starters to go on injured reserve, four of whom have hit the list since the loss at New England.
"Coach Fox mentioned how many obstacles the Patriots have overcome to be in this game. We've overcome a number of obstacles, as well, to get here," said quarterback Peyton Manning. "Starting way back to the offseason, starting back to maybe last season's playoff loss.
"It's commendable to the team that we fought through those obstacles and we put ourselves in this position and [are] playing a great football team [for the] AFC Championship. "
Extremly commendable, especially because neither team looks like its creators intended when they pieced together their rosters last offseason, let alone Week 12. Both teams evolved, survived, and found a way to thrive, regardless of injuries.