GREEN BAY, Wis. -- The most calming moment for a football coach comes when he realizes his quarterback can play -- really play. Not just function, but play at a level that makes everyone around him stop and take notice.

Brett Hundley has made that happen for two different coaches.

For Jim Ewan, it came during the second half of the second game of Chandler (Arizona) High School's 2009 season. With his team trailing Peoria Centennial big at halftime, he moved Hundley from receiver to quarterback and the junior nearly rallied his Wolves to a victory. Hundley never gave up the starting job.

For Jim Mora Jr., it came on the first snap of the first game Hundley ever played at UCLA, in 2012. The redshirt freshman quarterback kept the ball on a read-option and took it 72 yards for a touchdown against Rice.

For Mike McCarthy, he hopes that moment comes Sunday, when Hundley will make his first NFL start for the Green Bay Packers. McCarthy threw in Hundley after Aaron Rodgers broke his collarbone Sunday at Minnesota, but this week gives the Packers coach his first chance to devise a plan with Hundley as his starter.

"You have those moments, you go through those times with each and every guy," McCarthy said. "Probably this game is really Brett's moment because you really get to see him under duress, under adversity and really an uphill climb. I like the way he came through it, so hopefully we're standing here Sunday afternoon saying 'Hey, this was his moment, too.' I feel really good about Brett Hundley and the opportunity he gives us to win."

But, as McCarthy said, you never really know until you know.

In high school, Hundley spent his sophomore season on the junior varsity team even though Ewan's wife, Luann, an English teacher at Chandler High, said: "When he walked into the classroom the first day as a freshman, I announced to the whole class that he was something special and he was going to play in the NFL someday."

Even when Ewan moved Hundley up to the varsity late that season, he stuck with all-conference quarterback Kyle Yount, who won the job again the next season. That didn't last long. Early in Hundley's junior year, it became clear to Ewan and offensive coordinator Shaun Aguano that Hundley needed the ball in his hands on every play. As a junior, he threw for 1,517 yards with 16 touchdowns and two interceptions. As a senior, those numbers jumped to 2,348 yards with 20 touchdowns and two interceptions. He also led the team in rushing with 856 yards and nine touchdowns.

"He did it both his arm and his legs, and he just always maintained his composure," Ewan said. "I know everybody's probably ultra-concerned up there and when you lose Aaron Rodgers, you should be concerned. But he will be fine. He just doesn't get rattled. He has unbelievable composure."

At UCLA, Hundley redshirted as a freshman but won the starting job from day one the next season.

"When Coach Mora told Brett he was going to be the starter, he was so excited he physically fell off his chair," said then-UCLA offensive coordinator Noel Mazzone. "You could tell right away that it meant a lot to him."

Hundley started three consecutive seasons for the Bruins, then declared for the draft after his redshirt junior season. When he left, he was UCLA's all-time leader in touchdown passes (75), total offense (11,713 yards) and completions (837) and became the first quarterback to lead the school to three straight nine-plus-win seasons.

"I will tell you this: Before Brett ever started a game as a UCLA quarterback, he was voted a captain, and to me that said a lot about his team viewed him and his work ethic and his attitude and those necessary traits for a leader," Mora said. "He was a guy who just kind of took charge."

When McCarthy got testy earlier this week after he was asked about the possibility of bringing in Colin Kaepernick, he could've been asked about any veteran quarterback and his answer would have been the same. He bristled because he wanted Hundley to know that he believes in the 24-year-old even if at this point it's just an educated guess.

Those who have been around Hundley and have experienced those calming moments believe they know what's in store for McCarthy.

There's Ewan, who said Hundley will "do what he's always done. He'll study and be well prepared. He's always done a really good job of playing within himself."

There's Aguano, who this week texted another former Chandler star, Saints defensive end Cameron Jordan, and told him, "Lay off Brett a little bit this week," even though Aguano said Hundley can handle Jordan and anything else the Saints throw at him.

Then there's Mora and Mazzone, who keep going back to that first play.

"I figured I'd call the most basic play possible to start the game, a little zone-read play where he's supposed to give it to [future Packers running back] Johnathan Franklin," Mazzone said. "And he pulls it and goes 72 yards for a touchdown."

Said Mora: "You know his very first play as a starter was a touchdown, right? So maybe they can get that going on Sunday."