In November 2014, Tom Brady sent an email to a friend stating that Peyton Manning was in the "final chapter" of their storied rivalry while the four-time Super Bowl champion felt he had plenty left in the tank.
Though Manning laughed it off and Brady apologized for a message that was never intended to be mean-spirited - or public - the New England signal caller could be right.
After splitting their four postseason meetings, Sunday's AFC Championship game between Brady's Patriots and Manning's Broncos in Denver could be the last head-to-head matchup between these future Hall of Famers.
''It will be fun to play another Peyton Manning-led team,'' said the 38-year-old Brady, who extends his NFL record with a 10th conference championship appearance and fifth in as many years.
Brady's emails were submitted as part of the Deflategate investigation in August, and in one sent six days before the Patriots' 43-21 win over Denver in November 2014, he wrote of Manning: "I've got another 7 or 8 years. He has 2. That's the final chapter."
Brady is 11-5 against his friend, but Manning, who turns 40 in March, has won the last two in the postseason - both in conference championships on his home field. The most recent came two years ago this week, a 26-16 victory in Denver as Manning threw for 400 yards, two touchdowns and no interceptions. Brady went for 277 with a TD in the air and one on the ground in the fourth quarter, but the Broncos held the Patriots to 320 total yards.
"Tom is a good friend of mine, he'll always be a good friend of mine," said Manning, who is 3-0 in conference championship games since a 24-14 loss to Brady at New England with Indianapolis after the 2003 season.
Two seasons removed from the latest playoff meeting, their current roles and apparent longevity in the game appear much different.
Brady hasn't shown any real signs of slowing down. He topped 4,000 passing yards for a fifth straight season, led the NFL with 36 touchdowns and was picked off seven times despite dealing with injuries to multiple skill-position players and the offensive line.
''Doing the things that you've done to get yourself in this position are really important," Patriots offensive coordinator Josh McDaniels said. "His preparation, his rest and treatment and getting his body ready and his mind right. He does a lot of the things every day to prepare for the next day.
''Even though these games have finality to them that some games in the regular season or preseason don't have, he approaches it the same way.''
Manning played in 10 games while dealing with various injuries, most notably a reported partially torn plantar fascia. He was relegated to a reserve role late in the season before replacing an ineffective Brock Osweiler in a 27-20 victory over San Diego in Week 17. Manning, who threw 17 interceptions overall and just one of his nine touchdown passes in six home games, appears to be more of a game manager as his future grows more uncertain.
But while his body might be letting him down, Manning's passion remains. Trailing 13-12 in the fourth quarter last Sunday against Pittsburgh, Manning confidently led the Broncos on a 13-play, 65-yard drive capped by C.J. Anderson's 1-yard TD run with 3 minutes remaining. Manning, who threw for 222 yards and was victimized by several dropped passes, hit Demaryius Thomas for the 2-point conversion en route to a 23-16 victory.
"(No.) 18 is a little more amped up (for the playoffs)," Anderson told the Broncos' official website. "Making sure we're more dialed in and detailed on this and that."
While this potential swan song between the two greats provides a made-for-television storyline, the outcome could be decided by how well Denver's top-ranked defense can stop Brady and offense that averaged an AFC-high 29.1 points.
As Manning watched, a Broncos defense that yielded 283.1 yards per contest held the Patriots to 2 of 13 on third downs in a 30-24 overtime win in Week 12 to end New England's hope of a perfect season and drop Brady to 2-6 in the Mile High City. The Broncos overcame a 21-7 fourth-quarter deficit and three TD passes from Brady, who didn't have receiver Julian Edelman and lost tight end Rob Gronkowski to a knee injury late.
Denver scored 17 points in the fourth to force overtime and Anderson rumbled for 48 of his season-high 113 rushing yards on the winning score.
''Our confidence is perfect,'' Denver cornerback and ex-Patriot Aqib Talib said. ''We're good. We're playing a team who we beat earlier this year, we're at home, we're healthy. So, let's get it.''
Patriots linebacker Jerod Mayo is lost for the season with a shoulder injury and key Broncos special teamer Omar Bolden was put on IR with a knee injury. Denver All-Pro second team cornerback Chris Harris Jr. is dealing with a shoulder injury, but made additional headlines this week by telling ESPN that the way to tackle Gronkowski is to "hit him in the knees."
Edelman returned from a 10-game absence due to a broken foot to catch 10 passes for 100 yards in a 27-20 divisional-round win over Kansas City. Brady threw for 302 yards and both of his TDs went to Gronkowski, who shook off his lingering knee issue to make seven receptions for 83.
''The more of those guys you have out there the harder it is to defend,'' said coach Bill Belichick, who will match Tom Landry's NFL record by coaching in his 10th conference championship game. ''Tom knows what to do with them, he can find those matchups, that's what we need to do."
Gronkowski has 22 receptions for 283 yards with three touchdowns in his last three games against Denver, but he's listed as questionable for Sunday, along with Edelman.
After holding Pittsburgh to one touchdown and forcing a fumble prior to Manning's go-ahead scoring drive, Denver appears ready to step up again after improving to 10-3 in games decided by seven or fewer points.
''Our defense has been outstanding all season. They have led us to this point, let's make that clear,'' Manning said. ''Each game, key defensive players stepped it up, but you have to be a good team to win these playoff games and you have to win as a team.''
Thomas was held to one catch for 36 yards against the Patriots in November, but had seven for 134 and a TD in the conference championship victory two years ago.
That was one of three losses in six road playoff games for Brady, two of which have come in Denver.
''It's pretty hard to get to this point," Brady said. "There's only four teams standing. Two of these teams have to go home. Hope we're not one of them.''