Colts coach Jim Caldwell has the perfect backup plan. All he does is put in the next guy and get the same results.

The latest example came Sunday when Indianapolis used an undrafted rookie, Jeff Linkenbach, to protect Peyton Manning's blind side, and another undrafted rookie, Blair White, to be the critical No. 3 receiver.

They didn't miss a step in the 27-13 win against Denver.

"One thing my coach always tells us is, 'You're an ankle sprain away from being a starter, so you always have to be ready to go,'" defensive captain Gray Brackett said Monday, referring to longtime linebackers coach Mike Murphy. "The guys do a good job of preparing around here."

Actually, preparation has become a strong tradition in Indy's locker room.

Over the years, team president Bill Polian has been among the league's best at finding, and cultivating, talent in places others overlook.

Brackett, like Linkenbach and White, made the Colts as an undrafted free agent out of Rutgers. Four-time Pro Bowl center Jeff Saturday signed with the Colts after getting cut by Baltimore before training camp in 1998 and spending a full year out of football. Dominic Rhodes set an NFL record by rushing for 1,104 yards as an undrafted rookie out of Midwestern State, and this year's rookie crop is already writing a new chapter.

Linkenbach made his NFL debut at left tackle late in the first half of Manning Bowl II. Few noticed then, but the handful of plays he got in the Colts' home opener against the Giants helped the 23-year-old prepare for the biggest job of his life Sunday — taking care of the only four-time MVP in league history.

"You can't really look at it like that," he said. "Once the preseason is over, it doesn't really matter where you're drafted, you just have to go out and play. It was good for me to get a couple of drives in against the Giants. It helped me get my feet wet."

The Colts haven't said when Johnson, who missed more than a month of training camp with a sprained right foot, might return.

The bigger concern Sunday was at receiver.

With former first-round pick Anthony Gonzalez out with a sprained right ankle and No. 2 receiver Pierre Garcon out with a hamstring injury, Indy's three-receiver offense was down to two healthy players on the 53-man roster — Pro Bowler Reggie Wayne and emerging star Austin Collie.

So Caldwell promoted White from the practice squad to the active roster, and the offense stayed in sync.

Manning still threw for more than 300 yards and three TDs, Collie caught 12 passes for 171 yards and two TDs, and White had three receptions for 27 yards and one TD.

Linkenbach and White weren't the only guys to step in against Denver.

Starting linebacker Clint Session has missed two straight games with a hamstring injury and when his replacement, rookie Kavell Conner, injured his left leg or ankle late in the first quarter Sunday, backup Cody Glenn had to go in at a new spot.

No problem. Indy allowed only six points on five red-zone trips, as they pulled away for a 27-13 victory.

"That's just the mentality we have here," Glenn said. "I've been playing sam (strong side) pretty much the whole time I've been here, so I haven't practiced much at will (weak side). But I think I did a pretty good job, given the circumstances."

Despite losing Marvin Harrison for almost all of 2007 and Dwight Freeney for half of that same season, Brackett for the last four games of 2008 and Bob Sanders for all but nine games since the end of the 2007 season, the Colts have still won at least 12 games in seven straight seasons.

How do they do it?

By sticking to the plan.

"At the start of the season, I tell each and every guy on our team that whether you're on the practice squad or you're on the 53-man roster and in some sort of a backup role, that you have to prepare like you're going to play every single week," Caldwell said. "We try to stress it as much as we possibly can."

Nobody can argue with the results.