When Peyton Manning and Eli Manning lead their teams into Sunday's game between the Denver Broncos and New York Giants, it will mark the first time in NFL history that two starting quarterbacks meet with both coming off 400-yard passing games.
The brothers both know exactly how unlikely all of this seemed not so very long ago.
Eli reflected on how far-fetched this scenario seemed after Peyton underwent fusion surgery on his neck and was waiting for the nerves to regenerate, acknowledging that his brother was anxious about whether he ever would be the same quarterback.
"I knew it would get better with time," Eli told ESPN. "But after several surgeries and you're dealing with nerves -- you didn't know how quickly [he would recover]. That was the scary thing for him -- he didn't know how quickly it would get better."
Eli recalled throwing with his older brother after the 2011 season, when Peyton missed the entire season and was released by the Indianapolis Colts. The youngest Manning said his older brother struggled to generate any velocity on his passes, a source of concern for both quarterbacks.
"It just wasn't the same. ... It was frustrating and scary for him," Eli said. "He would look at me and say, 'What looks wrong? Why is it coming out without any pop?'"
Eli said he couldn't see anything wrong with Peyton's throwing motion, but the ball just looked like it wasn't being thrown hard.
Eli did not doubt that his brother would work as hard as necessary to recover. But the two-time Super Bowl MVP admitted that he wondered what would happen when Peyton actually returned to play in a football game.
"It's one thing throwing, and just dropping back and throwing, then avoiding the rush and throwing in awkward positions -- and you can't step into it," Eli said. "Can you get the same strength on the throw that you normally can to be successful?"
But Peyton has erased any doubts, especially after tying an NFL single-game record with seven touchdown passes in Thursday's season-opening blowout victory over the defending Super Bowl champion Baltimore Ravens.
Peyton, who passed for 462 yards against Baltimore, was named the AFC Offensive Player of the Week for a league-record 24th time Wednesday. The four-time league MVP also enjoyed an outstanding first season with the Broncos in 2012, when he passed for 4,659 yards and 37 touchdowns.
"He's obviously back and full throttle," Eli said. "After seven touchdowns, there isn't any doubt. And maybe there wasn't after 40 touchdowns last year. You know, he never ceases to amaze me."
Peyton acknowledged his brother's support Wednesday.
"Like all members in my family, they were all very supportive," he said. "It's nice to have that support when you're going through something different ... kind of an unknown injury with not a real set timetable. Eli was encouraging and supportive that whole time. I certainly appreciated it."
Eli also had a productive season opener, passing for 450 yards and four touchdowns despite throwing three interceptions in the Giants' turnover-plagued loss to the Dallas Cowboys. He hopes his older brother won't have a repeat performance of Week 1 when the Giants host the Broncos on Sunday.
"All you can do now is hope [Peyton] has gotten it all out of his system," Eli said.