After Schaub and backup Matt Leinart both had season-ending injuries, Yates was thrust into the job and guided the Texans to their first playoff berth.
Now the 24-year-old will lead the franchise in the biggest game of its 10-year history on Saturday in the first round of the playoffs against Cincinnati.
He bruised his left shoulder on a sack on Houston's first series last week against Tennessee and didn't play after that, but said he's fine and will be ready to play on Saturday.
Though he's played just six NFL games, Yates said he's been through so much that he feels he's been playing for a lot longer.
"It's been a long season," he said. "Even though I haven't been playing the entire season, I don't really feel like a rookie anymore. I've had a long time to get comfortable with this offense and comfortable with the teammates around me. Hopefully going into this playoff game, I don't have those rookie feelings anymore."
Star receiver Andre Johnson said Yates never behaved like a rookie and has been impressed with the quarterback's confidence. Yates already had that confidence when he entered the huddle prior to his first NFL snap after Leinart broke his collarbone in the second quarter against Jacksonville.
"He came in the huddle at Jacksonville with a smile on his face," Johnson said shaking his head. "He was just like: `Hey guys, let's go.' Most rookies would come in nervous and that's something you don't see in him. If he is nervous, he does a great job hiding it. I have a lot of confidence in his ability and what he can do."
Yates helped the Texans win that game at Jacksonville and one the next week against Atlanta, before rallying Houston from a 9-point deficit in the last six minutes for a 20-19 win over the Bengals. He found Kevin Walter on a 6-yard touchdown pass with two seconds left to give the Texans that thrilling win.
Yates believes having success against the Bengals in that game will boost the team's confidence as it prepares to face them again.
Houston has dropped three straight since then, including a 28-13 loss to Carolina in which Yates threw two interceptions. He said there have been a lot of difficulties in being thrown into this job, but the biggest one is that he's had to develop while the Texans were in a critical situation.
"Going through the learning process while this team was on a run and having some of those growing pains at the wrong time was kind of hurtful to the team," he said. "Every single game that I've played, whether I played bad or good or we won or lost, I've been learning every week and learning from my mistakes and just trying to get better."
He's been helped by a cadre of quarterbacks and a former quarterback in Houston coach Gary Kubiak with decades of experience. Schaub and Leinart are always there if he needs help or pointers. And the two players backing up Yates -- Jake Delhomme and Jeff Garcia -- have combined to play in the NFL for 25 years.
"They know that I'm hearing it from all angles and they do a good job of not giving me too much information or too much advice," Yates said of Delhomme and Garcia. "But having them to go through the experiences with me, they can reflect on what they've done in the past and it helps me a lot."
Kubiak and offensive coordinator Rick Dennison love the study skills of Yates. They say he studies so much that he's starting to absorb game plans as quickly as someone who has been in the league for years. Another positive quality they've seen in him is his resilience.
"If something doesn't come right away for him, he keeps working at it," Dennison said. "You never have to correct him about the same thing twice. If you do it one time, then he understands."
He'll have a weapon he hasn't had for most of his tenure as starter with Johnson expected to return to full speed this week after playing just seven games this season because of injuries to both hamstrings. Johnson played about 15 plays last week, but they didn't spend much time on the field together with Yates leaving early because of his injury.
The soft-spoken Johnson isn't the type to pester a quarterback about getting the ball. But he's hoping to make a big impact in this game after waiting nine seasons to reach the postseason and figures Yates is aware of that.
"T.J. knows where I'm at," Johnson said with a laugh when asked if he'll be in Yates' ear Saturday.
Yates is excited to have Johnson back not just for his playmaking abilities, but for how he changes the way opposing defenses play the Texans simply by being on the field.
Johnson has just 492 yards receiving with two scores after finishing with more than 1,200 yards receiving in each of the past three seasons, including a career-high 1,575 yards in 2008.
"I'll definitely know where 80 is the entire game," Yates said. "He's definitely someone I'll be looking for on Sunday."
Another thing Yates is sure of concerning this game is that his parents will have better seats than they did the last time Houston played the Bengals. CBS commentators Marv Albert and Rich Gannon had a good time making fun of the Yates' seats at Paul Brown Stadium, which were on the second row from the top of the highest deck in the place. Their terrible seats seemed even worse with thousands of better empty seats throughout the stadium.
"Yes, they will definitely be a little closer," Yates said with a chuckle.