LAKE FOREST, Ill. (AP) — Kyle Orton insisted things will be different this time. The jittery rookie whose job was simply to hand off and not turn the ball over is all grown up, ready to lead the Chicago Bears rather than simply tag along.

"I've been in the system a lot longer. I've been in the NFL a lot longer. And I'm a better pro," Orton said Wednesday.

He has a chance to prove it in prime time Sunday night when the Bears open the season at defending AFC South champion Indianapolis in what figures to be a frenzied atmosphere. Not only are the Colts opening a new stadium, they also boast one of the league's top defenses. And that could mean a tough night for Chicago.

Coming off a disappointing 7-9 season following a Super Bowl run, there's a long line of questions hovering over the Bears. Particularly on offense.

The line got a makeover. So did the receiving corps and backfield, and the man lining up behind center spent most of the past two seasons watching from the sideline.

While Chicago tries to contain Peyton Manning, the Bears' offense will be nose to nose with a defense that ranked third in the NFL. It's a big obstacle and a big opportunity.

"I'm excited. This is a great chance for not only myself but the offense to go out and make a statement against a very good defense," Orton said.

In three seasons, Orton is 12-6 as a starter and has the fourth-highest winning percentage among Bears quarterbacks with at least 16 starts since 1961. Yet, he's also unproven.

Orton spent most of the past two seasons watching from the sideline, and his duties were limited even when he started 15 games as a rookie in 2005. A fourth-round draft pick out of Purdue, he got thrust into the role that year when Rex Grossman suffered a broken ankle in the preseason and went 10-5 running a simplified offense.

Orton's job: Hand the ball off and don't turn it over. He completed just 190 of 368 passes (51.6 percent) for 1,869 yards and threw more interceptions (13) than touchdown passes (nine).

Even so, the Bears won eight straight following a 1-3 start. But fans were clamoring for Grossman after a loss at Pittsburgh in December. A week later, the crowd at Soldier Field erupted when he trotted onto the field in the second half against Atlanta.

They wanted some versatility and got it.

Grossman added the deep pass to a run-based offense when he returned and played at a Pro Bowl level early in the 2006 season, before falling out of favor because of his inconsistent play. He was benched for Brian Griese after throwing six interceptions and one touchdown in the first three games last year.

Grossman returned for five more games and played better, passing for 913 yards with three touchdowns and one interception before injuring his left knee.

That created an opening for Orton, who never left the sideline in 2006. He responded by completing 43 of 80 passes for 478 yards with three touchdowns and two interceptions as Chicago won two of the final three games, and that was enough to persuade the Bears to open up the competition.

They made it official when they signed Orton to a one-year extension that runs through 2009 in late February, two days after re-signing Grossman for one year. The competition began during offseason workouts and heated up during training camp, with coach Lovie Smith announcing Orton the starter before the third preseason game.

"He has a lot more experience (now)," Smith said. "He's been through quite a bit. He's had a chance to sit on the sideline and watch. He's had a chance to develop his body, his mind. All the things you get from experience, Kyle has had an opportunity to do."

Wide receiver Rashied Davis sees a more mature quarterback.

"He's more confident. He's more knowledgeable," said Davis, a backup cornerback in 2005. "He's put in a lot of time trying to get better and focusing on fundamentals. He's a lot better than he was as a rookie when he started."

Three years ago "he probably wouldn't be as confident in the protections and knowing where to set the protections," Davis said. "But he's a lot more confident now."

Now, after a long road, Orton is starting another opener. It was a long road, right?

"It seems like a long time for me, but this is only my fourth year," Orton said. "I've worked hard to get to this point and hopefully, I'll take advantage."