(Eds: Updates with details, quotes. With AP Photos.)

By CHRIS DUNCAN

AP Sports Writer

HOUSTON (AP) - When the Texans opened training camp, right tackle Eric Winston wasn't expecting much from the incoming rookie class.

It wasn't that Winston lacked confidence in the choices coach Gary Kubiak and general manager Rick Smith made in the draft. Winston just hadn't seen many first-year players mature quickly enough to make dramatic impacts.

J.J. Watt, Brooks Reed and T.J. Yates turned out to be exceptions.

The three have played pivotal roles in helping the Texans (11-6) survive a myriad of injuries to reach the postseason and advance to the second round. Houston plays at Baltimore (12-4) on Sunday for a berth in the AFC championship game.

Any time you have this many injuries and you have contributions not from vets, but from rookies stepping up and making big plays in big games,'' Winston said,that's why a team goes as far as it does.''

Watt, who's started all 17 games at defensive end, leads the Texans in tackles for loss and made the defensive play of the season, returning an unlikely interception for a touchdown in last week's 31-10 win over Cincinnati.

Yates kept Houston afloat after season-ending injuries to quarterbacks Matt Schaub (right foot, Lisfranc) and Matt Leinart (broken left collarbone).

Reed ably moved into a starting role at outside linebacker and made sure the defense didn't miss a beat when star Mario Williams went down.

You never know how a season's going to go,'' Winston said.You never know if you're going to be blessed from an injury standpoint, or you're going to have to have guys that have got to go (play).

``We've definitely had one of those years that we've had guys who've had to go.''

The 6-foot-5, 288-pound Watt was pegged as a starter from the moment Houston took him with the 11th overall pick. Texans fans were initially turned off by the selection, with more recognizable names still on the board, and Watt took notice.

I remember a lot of people in Houston's reaction on draft day and obviously, I don't have any problem with it,'' he said.It was warranted at the time. But it was always my goal from Day 1 to prove to them that I was the football player that the city of Houston would hopefully come to love and I'll always continue to work to make the city proud.''

And Watt proved to be NFL-ready, manhandling linemen and swatting away passes from early on in August workouts. He recovered a fumble in the opener, got his first sack in the third game and won over fans with his relentless energy.

Then came Saturday's playoff game. Watt timed his jump just like he's done in practice all season, snatched Andy Dalton's pass with both hands and sprinted 29 yards for a score that put the Texans ahead to stay.

``You want your top picks to be a good player, but they usually don't develop that quickly,'' defensive coordinator Wade Phillips said.

The 6-3, 250-pound Reed was a second-round pick out of Arizona. He moved into the starting role after Williams tore a chest muscle in Week 5. He played defensive end in college, and has made a seamless adjustment to outside linebacker, with six sacks, three pass deflections and two fumble recoveries this season.

You know, you lose Mario Williams, you've got to step in there for Mario Williams,'' Kubiak said,so how's he going to react to that? We knew he'd be a good player, but I think the job he did as quickly as he's done has been exceptional.''

Yates, a fifth-round pick, was also thrown into the starting role earlier than expected. The Texans liked him because he played a similar offensive scheme at North Carolina.

He became an instant hero in Houston after winning his first two starts, then struggled in his next two, both losses. He had modest numbers against Cincinnati - 11 for 20 for 159 yards - but saved his best throw for when it mattered most, dropping a perfect 40-yarder into the arms of Andre Johnson for a touchdown in the second half.

As with Watt and Reed, Yates' maturity and performance have won over his teammates.

As a rookie quarterback, for not being dressed in the beginning of the season, holding the clipboard, and then being thrown in the fire, I'm extremely impressed,'' Winston said.I'm in the league for nine years, and you see some guys just get the jitters, and not just the quarterback, but every position. Having the jitters is a good thing, but he does a great job of staying relaxed and poised, and that's what you need at a quarterback position.''