Five games into the season, Manning is off to another perfect start, has set a team record with five straight 300-yard games, and is reaching milestones on a weekly basis. Next up: The NFL mark for most consecutive 300-yard games, which he could tie on Sunday against the St. Louis Rams.

"He is playing outstanding, and I think that is an understatement," Caldwell said after Manning's last victory at Tennessee. "He's always been excellent since he arrived here, but he's at a different level now."

Caldwell is not the only one who has seen changes this season.

Coaches from Seattle's Jim Mora to Tennessee's Jeff Fisher have publicly stated how impressed they've been with what they've seen on tape _ and in games _ from the 33-year-old Manning. They all believe Manning is getting better, and the numbers prove it.

Since Week 1, Manning has passed Hall of Famer Fran Tarkenton for third on the NFL's career list for touchdown passes and broken Hall of Famer John Unitas' team record for wins by a quarterback. On Sunday, Manning can join Steve Young, Kurt Warner and Rich Gannon as the only players in league history with six straight 300-yard games.

"He's at a point in his career where the records are starting to fall because of his consistency," tight end Dallas Clark said. "When you're at the top tier at your position for as long as he's been, the records are going to fall."

The question is how many can Manning break this year?

He is on pace to complete 426 passes, which would be second in league history to Drew Brees' 440 last year, and throw for 5,264 yards, which would be another single-season NFL record. Those numbers could fall short, though, if the Colts continue to hold a commanding lead in the AFC South division and Manning is rested during games.

Manning isn't looking that far ahead.

"We're off to a good start, but we have a ton of football left to play," he said. "Guys are professional in their preparation. Those are good first steps. Hopefully, we can keep making plays on the field."

With Manning playing this way, it shouldn't be a problem.

Manning's league-leading completion percentage of 73.5 also puts him on course to break Ken Anderson's single-season mark of 70.55 percent, set in 1982.

Manning remains meticulous in his preparation. He still keeps the focus on his work, staying consistent and doing whatever it takes to win games _ regardless of numbers, records, personal accomplishments or accolades.

"It's really hard for me to put what's going on this year and comparing it to, say, last year," he said Wednesday. "Each year is different, each year the team forms its own identity."

Next comes a young, winless St. Louis team ranked 27th against the pass and seemingly ripe for Manning to dissect. After that, it's San Francisco's 20th-ranked pass defense.

"It's really unbelievable what he is able to do. You watch film, and you can just see the kind of control he has, the patience," St. Louis rookie linebacker James Laurinaitis said. "It's hard to simulate in practice. It's one of those things that you can't really simulate, how Peyton controls the game. You try to do one thing, and he's just going to do the other."