HOUSTON -- Three days before he would lead the most important drive in Houston Texans history, T.J. Yates sat in an empty locker room under Reliant Stadium and mused about his long, strange trip to the top of the depth chart.
Starting quarterback Matt Schaub, who led the NFL in numerous passing statistics two seasons ago, broke his right foot in Week 10. Backup Matt Leinart was lost in the next game to a broken collarbone. Yates -- a rookie from North Carolina who was the Texans' second pick in the fifth round and the 152nd player taken -- found himself the Next Man Up for Houston.
"It's kind of far-fetched when you're the third-string guy and you're a rookie," Yates said, shrugging. "People are skeptical. But I've been preparing all season long as if I was going to play."
Before Yates' first NFL start, Texans coach Gary Kubiak gave him a challenging test: knowing the coverages and reads associated with each of Houston's 60 offensive plays. The confident but unassuming kid aced it. The Texans, improbably, beat Atlanta in Week 13 and Yates didn't hurt them.
Last Sunday in Cincinnati, he won the game. With no timeouts and a little more than two minutes on the clock, he took the Texans 80 yards. The last of his 300 passing yards came on a 6-yard touchdown pass to Kevin Walter with two seconds left. Houston won 20-19 and clinched a playoff berth for the first time in its decade as an NFL franchise.
Two stories -- Tim Tebow, and the undefeated Green Bay Packers -- have dominated NFL coverage this season, but the Texans have been a revelation. Houston, not Denver, has the second-longest winning streak behind the Packers; the win in Cincinnati was its seventh straight.
And like the Packers, who overcame an injured reserve list with 15 players to win the Super Bowl a year ago, the Texans (who have placed a dozen on IR) have persevered despite injuries to core players.
"It's easy when those injuries start building to start feeling sorry for yourself and say, 'Maybe it's not our year,'" said offensive tackle Eric Winston. "But no one said that around here. No one's allowed that to creep into their mind."
Houston has been solid the last three years, going 25-23, but has never been able to get past the Indianapolis Colts and into the postseason. This year, with pressure on Kubiak to reach the next level, the Texans have produced their finest season.
"This year is just a year of no excuses," said linebacker DeMeco Ryans, the defensive leader. "The next man is to step up and fill his role. So many past letdowns in previous years, so many times so much adversity has faced us and we didn't respond well to it.
"Coming to this year, it doesn't matter what happens, doesn't matter who goes down. It doesn't matter what hits us in the face, we've got to keep going, keep fighting and find a will to win."
Defensive coordinator Wade Phillips, the most important offseason acquisition for Houston, said last week it's a message Kubiak has stressed all season long. Perhaps, Phillips observed, Kubiak feels that way because Kubiak was a longtime backup for John Elway in Denver. Phillips took a medical leave of absence Wednesday and will probably miss a few weeks
"Coach Kubiak kind of makes a point to tell everybody in front of the team that it's your time to step up and single that person out," Yates said. "I think that makes that person rise to the occasion."
Yates is the Texans' best example. After Michael Vick and Jay Cutler were injured, the Philadelphia Eagles and Chicago Bears struggled. Yates, meanwhile, is 2-0 as a starter and helped the Texans become the first team in eight years to win three straight games with three starting quarterbacks.
When Arian Foster, the league's 2010 rushing leader, missed two games early in the season, backup Ben Tate produced two 100-yard games. Was Foster, who was nursing a hamstring injury, worried about losing his spot?
"Nah," Foster said, laughing. "He stepped up when he had the opportunity. People forget this is how we feed our children, how we keep our lights on. At the end of the day, we all still have a job to do."
Foster has run for 957 yards and Tate has 820, giving them a combined 1,777 yards and 11 touchdowns, which makes them the No. 1 tandem in the league. The running game, led by an excellent offensive line, has also helped compensate for the loss of wide receiver Andre Johnson, who has missed seven games with injuries to both hamstrings.
In Week 5, linebacker Mario Williams -- the team's best pass-rusher -- was lost for the season with a torn pectoral muscle. Weakside outside linebacker Connor Barwin (40 tackles, 9.5 sacks) and strongside outside linebacker Brooks Reed, a second-round draft choice from Arizona (39 tackles, six sacks), have helped compensate. Barwin had four sacks in a game against Jacksonville.
"Nobody's going to go in there and get 15 sacks [Williams] was on pace to do, but it was rush-the-passer-by-committee," Barwin said. "When people have gone down, the guys who have stepped in at that immediate position have all elevated their game. I think the theme is we've got a pretty good team."
The defense, ranked No. 30 a year ago, is currently No. 1. Under Phillips' 3-4 scheme, Houston allows an average of 274.9 yards per game. It allows 16 points per game, No. 4 in the league.
In Cincinnati, the Next Man Up helped overcome a 16-3 halftime deficit. Yates completed 26 of 44 passes for those 300 yards. In addition to two touchdown passes, he ran five times for 36 yards, including a 17-yard scramble on third-and-15 on the final drive. Tate was the Texans' leading rusher with eight carries for 67 yards. Barwin had a sack and forced a crucial fumble that led to the Texans' first score in the second half.
When the Saints beat the Titans, the Texans were the first AFC team to make the playoffs. Johnson, whose teammates call him the best player in the league, was given the game ball.
"Words can't really describe it," said Johnson, who watched the game from the sideline. "It's something I've been waiting for for a long time."
The Texans, who have the No. 2-ranked running game and that surprising defense, have proved they are not out of their depth, that they can win with Yates. The remaining schedule -- Carolina, at Indianapolis, Tennessee -- suggests the Texans can challenge the AFC's other three 10-3 teams for a first-round bye.
Brisiel broke his leg in the first half of the game in Cincinnati. In the true spirit of these Texans, he played the entire second half.
Greg Garber covers the NFL for ESPN.com.