USC's likely backup quarterback this week wears No. 27, spent the spring as an emergency safety and still has to be on call for special teams work in practices.

Meet walk-on Brandon Perdue, who will be next on the No. 21 Trojans' perilously thin QB depth chart behind Matt Fink if Kedon Slovis (concussion) is either not medically cleared or held out as a precaution on the road at No. 17 Washington on Saturday.

"I've always wanted to be out there and try to help my guys any way I can, whether it's at scout team, at safety, wherever it was. And right now, in this moment, it's as a backup quarterback," Perdue said Tuesday. "That's where my heart's at and that's helping this team any way I can."

Perdue took the second-team QB reps at practice Tuesday and indicated he got some extra work in whatever package the coaches have put together for him in the event he's needed Saturday.

When USC released its depth chart at the end of August, Perdue wasn't even listed as one of the five QBs (which included fellow walk-ons Trevor Scully and Scott Harris). He was instead listed as the fourth-string free safety -- a position he had never played in his life before moving there in the spring to give the Trojans a healthy body in what was at the time a barren secondary.

"Like I said on my first day with coach Helton, I told him anything to help this team win a championship and anything he needed or wanted I'd be willing to do. So when he told me he needed a safety to give not only the offense but the defense a look, I was happy to do it," Perdue said.

Just as he's on call for special teams coordinator John Baxter in practice -- even this week, while not wearing the usual yellow non-contact jersey standard for QBs.

"When coach Baxter wants me to go out there and give the guys a look, I will. I'm out there making contact here and there," Perdue explained.

Such is the life of a walk-on -- it just so happens that this week for USC, Perdue is relevant enough to draw a gaggle of reporters after practice. And he did indeed have a cool story to tell.

The redshirt junior from Oaks Christian High School in Westlake Village played in just two games as a senior there with 19 pass attempts. He was appreciative to have an offer to play at Pace Univeristy in New York, and while he liked the coaching staff, he said it simply wasn't the environment he was seeking.

"Football's not necessarily a priority, and for me football was at that time of my life, so I wanted to take my crack at it," Perdue said. "I literally remember I would wake up having dreams about playing at 'SC or playing in a big stadium so I decided I wanted to go home and take my shot at JUCO and go from there."

His circuitous path took him to Pierce College in Los Angeles where he played 4 games in 2016 (59 pass attempts) before getting injured, and then he was off to New Mexico Military Institute where he completed 16 of 30 passes for 163 yards, 2 TDs and 1 INT in 2017.

With that, he thought his football days -- and those dreams of playing at a big program -- were over before a series of events opened a new door.

"I didn't choose to come here necessarily. It was kind of where I was supposed to be," Perdue said. "My brother was actually accepted to do his PhD here [at USC] in the spring of 2018 and when he did I kind of filled out an application jokingly, and when I got accepted and some things fell through with my recruiting I just decided that I was going to be done with football and just come here and be a student.

"Within two days of being here, one of my friends on the team, Holden Thomas, was a quarterback and he let me know he had some elbow injury going on and the guys needed help, they needed a scout team quarterback. So he shot my film over to Sam Curtis (now USC's director of football operations), another great guy, and when he saw it he said, 'Well why the heck aren't you out here?' That Tuesday I was in pads helping the guys out."

If Slovis is held out this week and Fink has to leave the game for whatever reason, expect the Trojans to get creative. Perdue will have a limited package of plays the staff feels he's comfortable running. But they also had wide receiver Tyler Vaughns take some snaps at quarterback on Tuesday.

"If Fink were to go down you've got to have a plan. It's just not an ideal situation," offensive coordinator Graham Harrell said. "... Like I said, we'll figure it out. We plan on playing Fink, and again, if something happens, now you're in a scramble situation and you've got to make the best of what you got."

Head coach Clay Helton, meanwhile, was asked for a scouting report on Perdue.

"He's been a quarterback on our service team last year as well as this year. I watch all the tape, and he goes over there and does a tremendous job and he's a competitor," Helton said. "He's a good athlete. ... Has a talented arm, has arm strength, still has enough in the package to move the ball. I'm hoping that we don't get to that point, but we are prepared for it."

Said Perdue: "I've played quarterback my whole life so this isn't too shocking for me, this isn't too much to put on my plate."