Ty Dieffenbach took a snap from the center, faked a handoff and dropped back before throwing a short pass early in practice Tuesday.

Then it was on to a series of slightly longer passes before the UCLA quarterback completed one drill in which a teammate tried to knock the ball out of his hand and another drill in which staffers took turns whacking him with blue pads.

It all looked so routine. It had such a familiar feel. 

And yet it was nothing like anything Dieffenbach had experienced before.

He’s now a starter at the most pivotal position for the 12th-ranked team in the country after Nico Iamaleava sustained a knee injury that is expected to sideline him for the season.

If that sounds like a lot to handle for a college kid to handle, consider what Dieffenbach pushed through in high school.

He won the starting quarterback job as a sophomore, beating out a senior. He bravely faced his mother’s bout with breast cancer and was a steadying senior captain who served as the face of the program after a teammate died. 

When his final high school season ended prematurely because of injury, he stuck around to mentor his replacement rather than abandon a team that went 1-9.

So, no, taking over as the Bruins’ quarterback midway through the season is probably not going to fluster him.

“I believe he lives for it, man, and he’ll have that sense of quiet in him that he’s tough and this isn’t too big for him,” Dustin Croick, who was Dieffenbach’s coach at Agoura High, told the California Post.

The coach FaceTimed his former star Sunday, one day removed from the biggest game of his life.

Replacing Iamaleava midway through the Bruins’ game against Oregon, Dieffenbach threw the touchdown pass that provided the decisive points and fearlessly managed the offense during a 17-15 victory.

“I thought his poise was really inspiring,” tight end Josh Phifer said, “because being in the huddle and just seeing that your quarterback is not really nervous or freaking out at all and just ready to go attack makes the rest of the offense just feel comfortable too.”

Dieffenbach has come a long way since he was a skinny high school sophomore who took over as the starting quarterback despite never having previously played the position.

“It was really, really awesome for me to have somebody that was just that raw, that was super into it, that didn’t have any preconceived notions or anything about the position or wasn’t taught he needed to do this and be this and that,” Croick said, “so it was just super genuine of like, all right, we’re just trying to make him a quarterback.”

It was a rapid ascent, Dieffenbach developing his skills and showing leadership by getting teammates to wear certain school colors on designated days. By his junior season, he led the Chargers to a 7-3 record while breaking the single-season record for touchdown passes. That was when other teams came calling, trying to lure the budding star away.

He refused to budge, remaining loyal to his school and teammates. Then, just before his senior year, a teammate died and Dieffenbach galvanized the locker room.

“That was a lot for a kid like that to take on because there was a lot of media attention around that, not to mention losing a teammate and all that,” Croick said. “He was the face of the program at the time and he just handled that really well.”

Even though he barely played as a senior because of his injury, Dieffenbach was recruited by multiple schools. He initially committed to UNLV before Pittsburgh swooped in late and he agreed to become a Panther.

But he never played during two seasons that included a change at offensive coordinator. A transfer to Cal Poly in San Luis Obispo led to a starting role – and more frustration. Dieffenbach had pockets of success during a 4-8 season, throwing for 1,305 yards and nine touchdowns with nine interceptions.

A previous relationship with former Holy Cross offensive coordinator Dean Kennedy paid off when Kennedy followed Bob Chesney from James Madison to UCLA and offered Dieffenbach a spot on the team.

He agreed to come for his senior year, though there was no assurance of playing time with Iamaleava entrenched as the starter and younger brother Madden Iamaleava vying for the top backup role.

Last weekend, in an awful instant on the field at Autzen Stadium, all that changed.

Croick said he believed Chesney was the perfect coach to unlock Dieffenbach’s potential.

“He probably believes in Ty and he’s all about just getting better every day,” Croick said, “and that’s what Ty needs.”

As Dieffenbach and the Bruins (5-0 overall, 3-0 Big Ten) prepare to face Wisconsin (4-1, 2-0) on Saturday at the Rose Bowl, Croick knows for certain the one person who believes in his former quarterback.

“He believes in himself,” Croick said. “Regardless of Pitt or Cal Poly and what happened there, he’s going to grind, he’s going to work. … I’m biased, but I think he’s going to kill it. This is the opportunity that he’s been waiting for.”