MIAMI -- Former Colts coach Tony Dungy used to preach in team meetings that if a player went down with an injury, "the next guy just had to step up."
As it turns out, the "next guy'' premise is one of the reasons the Colts are in the Super Bowl.
Injuries rocked the secondary early in the season. All-everything safety Bob Sanders played only two games before injuries ended his season. Kelvin Hayden, the league's least-known $8.6 million-a-year cornerback, was hurt after two weeks and played only sporadically the rest of the regular season. Cornerback Marlin Jackson, a former first-round pick, played only four games because of injuries and started none.
The "next guys'' ended up being a safety (Melvin Bullitt) whose style is similar to his name, a third-round rookie (Jerraud Powers) who might have been the best cornerback to come into the league this season and an undrafted rookie corner (Jacob Lacey) who somehow managed to survive and play very well.
Heading into Super Bowl XLIV, the Colts' secondary, which could have been labeled a disaster area, is much better than outsiders think. To survive Sunday's showdown against Drew Brees and the Saints' No. 1-ranked scoring offense, the Colts' secondary must hold together and play its best game of the season.
"In training camp, Coach [Jim] Caldwell always started off by saying this is a team of 61 guys, including the guys on the practice squad,'' Hayden said. "He said that during the year, he guaranteed that everybody would be needed and we need for these rookies and young guys to buy into that."
What helped was the ability of general manager Bill Polian to find athletes who are intelligent enough to learn the Colts' Cover 2 scheme and be able to play it when called upon. Not many teams can get only 10 starts out of three-fourths of their starting secondary and advance to the Super Bowl.
Safety Antoine Bethea held everything together all season. Bethea is one of the NFL's better safeties but is unheralded among fans. Players and coaches know him. He has been a Pro Bowl alternate the past two seasons and is gaining a reputation as one of the league's smarter safeties. His leadership held the Colts' secondary together at the most crucial time of the season -- when everyone was going down with injuries early in the season.
"You have give Antoine a lot of credit because he did a tremendous job of keeping us together and making sure we kept up our confidence," Powers said.
Injuries hit the Colts' secondary so hard at the beginning of the season that rookies Powers and Lacey had no time to think. Bethea calmed down the rookies and got them through the first few starts.
"All the injuries happened in about a two-week period early in the season," Powers said. "Antoine talked to us and said, 'You guys know how to play football, so just go out there and play.' He told us [to] not be afraid to mess up because he had our backs."
Powers and Lacey combined for 21 starts but surrendered only three touchdowns between them. At first, they were tentative, but they eventually got comfortable.
The Colts' Rod Perry, one of the league's better secondary coaches, marvels at how this secondary held together this season. When the Colts lost Sanders, most outsiders thought the secondary would fall apart. But defensive coordinator Larry Coyer didn't change up the scheme even with Sanders out.
"It's still the same scheme because we fly to the football,'' Bullitt said. "That's the one thing we thrive on. Bob is an awesome player. When he's on his game, he's unbelievable. And he'll be back next year."
Opponents completed 63.5 percent of the passes against the Colts, but Indianapolis' strategy is to keep those who catch the ball in front of the defenders and not allow big plays. Without Sanders, and using two rookie starters most of the season, the secondary allowed a modest 6.23 yards an attempt and was beaten for 19 touchdowns.
"Even without Sanders, we've still got to go out there and play our style of ball," Bethea said.
Two big concerns for the Colts' defense this week are the ankle of defensive end Dwight Freeney and the foot problems of Powers. Freeney is questionable with a third-degree right ankle sprain. Powers is just starting to recover from a foot injury that made him a nonfactor in the Colts' past two playoff games.
Having Powers available to start or even play nickel is vital to the Colts against the Saints. Tim Jennings would play more if Powers is limited. Two-thirds of the pass attempts thrown in his area have been completed and he surrendered five touchdown passes during the regular season.
John Clayton, a recipient of the Pro Football Hall of Fame's McCann Award for distinguished reporting, is a senior writer for ESPN.com.