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Sunday was supposed to be Matt Leinart's chance at once again showing he could be an NFL quarterback.

Leinart's Heisman Trophy, won after a stellar career at USC, no doubt shines brightly somewhere in his home, but his star hasn't been as luminous at the professional level.

An injury in 2007 ended his first stint as a starting quarterback with the Arizona Cardinals, while poor play and the presence of Kurt Warner prevented him from reclaiming the role for the franchise that selected him 10th overall in the 2006 draft before his eventual release prior to the 2010 campaign despite Warner's retirement.

Given a third shot with Houston because of a season-ending foot injury to franchise signal-caller Matt Schaub, fate played a cruel mistress to Leinart in his return. A likely broken collarbone, the same injury that derailed Leinart's career in '07, knocked him out of Sunday's start versus the Jacksonville Jaguars before he had even completed a half.

Yes, the 28-year-old has been down this road before. Literally.

"It's pretty disappointing. As of now, it doesn't look too good ... I think there's a pretty strong possibility that I won't be coming back this season," Leinart said after Houston's 20-13 win, adding he would wait and see what the doctors say.

The range of emotions that Leinart must have felt on Sunday seem excruciating. At one moment, he was hitting tight end Joel Dreessen for a 20-yard touchdown pass. The next, Leinart was coming off the field after landing hard on his left shoulder following an incomplete pass.

"It was exciting to have fun playing again," said the quarterback. "I went from an ultimate high to an ultimate low with the injury. It's the nature of the game, but this was a great team win for us."

Leinart was quick to say after the game he is in no way giving up following his latest setback. That is the same mentality that the 8-3 Texans now must have. Looking for their first ever playoff appearance, Sunday's win over Jacksonville kept Houston two games ahead of second-place Tennessee in the AFC South standings.

The best thing for the Texans would be to wrap up a playoff spot as quickly as possible, but that could unfortunately take some time. With the AFC North primed to get three teams into the postseason, a division title could be Houston's only route to the playoffs. Though the Texans do own one win over Tennessee this year, it won't play the Titans again until the regular-season finale at home on Jan. 1.

In the span of three weeks, rookie T.J. Yates has gone from the third quarterback to the starter for a playoff-contending club. He threw for 70 yards in relief of Leinart, but the Texans managed only two field goals with the University of North Carolina product under center.

The 24-year-old Yates figures to be better prepared for this Sunday's home game versus Atlanta and should benefit from the help a talented running back group that includes Arian Foster, Ben Tate and Derrick Ward will provide.

"It's going to be different during the week just getting more reps," Yates said. "I prepared this week as if I was going to be the starter just with that cliche [that] you're one play away. It happened this week, but I was ready to play."

For his part, head coach Gary Kubiak, whose club is on its first single-season five-game winning streak in team history, also thinks another week of reps will help his young quarterback.

"He just plays the game fast," he said of Yates. "He's shown me all of the characteristics you want to see in this league. He can move; he has a good arm. But the bottom line this is the first reps the kid's gotten. He can only get better and I know the team will do everything they can to rally behind him."

With Leinart likely done for the season, the recently-signed Kellen Clemens steps in as the backup after serving as the third quarterback on Sunday, and Houston again is in search of another quarterback to add to the roster. Jeff Garcia, Trent Edwards, Brodie Croyle and Chase Clement were among those to have reportedly worked out with the Texans along with Clemens.

Things have gotten much tougher for the resilient Texans in their quest for the postseason, but don't expect Kubiak's crew to call for mission abort.