Released last week by the Arizona Cardinals, Leinart practiced with the Texans for the first time since agreeing to a one-year deal with the team Monday.
The 2004 Heisman Trophy winner will be the third-string quarterback when the Texans open the season against Indianapolis on Sunday. It's a humbling fall from the high expectations he brought to the NFL after three spectacular seasons at Southern Cal.
But Leinart calls his one guaranteed season in Houston a "new chapter," and one he hopes will revive his NFL career.
"Obviously, the first four years, they didn't go the way you would hope and the way I hoped," he said. "I learned a lot as a quarterback, and as a person. I had a chance to learn from Kurt Warner, who is one of the greatest quarterbacks to play. Now, I get a chance to come here and learn from Matt (Schaub), who's become a pretty good quarterback in this league.
"It's unfortunate that it worked out like that over there (in Arizona)," he said. "But like I said, this is a new chapter, this is a fresh start, a new offense. I'm just excited."
He spent most of the day with quarterback coach Greg Knapp, getting his first taste of the complex offense that led the NFL in yards passing in 2009. He threw an interception on a short route in practice, then threw a deeper pass on target that was dropped.
Leinart said the Texans' offense is closer to what he learned in college than in Arizona. Some of Houston's offense is similar to what the Cardinals ran, but Leinart will have to memorize new terms for old plays.
"It's hard. It's not a position I've been in in awhile," he said. "There is just so much stuff, I'm trying to soak it in. In Arizona, we had a lot of the same concepts. The terminology and the words are just completely different. One word meant something there, and then the same word means something completely different here."
Leinart led the Trojans to two national championships and a third title game. He was drafted 10th overall by the Cardinals and appeared in 12 games as a rookie under coach Dennis Green, throwing 11 touchdowns and 12 interceptions. He broke his collarbone in the fifth game of the next season, Warner took over and Leinart watched from the sideline over most of the next 2½ seasons.
Warner retired after the 2009 season, giving Leinart a chance to run the offense. But Leinart openly complained about his relationship with coach Ken Whisenhunt, Cleveland castoff Derek Anderson won the job in training camp and Arizona started shopping Leinart.
When the Cardinals couldn't find a good deal, they cut Leinart and saved themselves the $2.5 million that he was due to make this season.
Leinart chose his words carefully when he talked about his final days in Arizona.
"The thing I've learned, especially the last couple of years, is control what you can control," he said. "I worked hard, I prepared hard for this season, this preseason. I thought I played well and had a good training camp. It just didn't go as planned. Coach (Whisenhunt) decided to go in a different direction. We had our differences, but I think we respect each other and it was time to move on, obviously."
After he was cut, Leinart said he went to the beach in California and mulled offers from teams that showed interest in him. Seattle, now led by former Southern Cal coach Pete Carroll, was one of them, but Leinart said the Seahawks chose to go "in a different direction in their quarterbacks, as far as how many they were taking."
He said the Texans presented the most ideal situation, even though he isn't likely to see much action backing up Schaub and Dan Orlovsky.
"My goals are just to work as hard as I can, to pick it up and study as much as I can, and just be prepared to play if I'm ever called upon," he said. "That's the mindset of a quarterback, especially when you're not the starter. I just want to learn, I want to get better as a player."