COSTA MESA, Calif. -- No two paths to becoming an NFL quarterback are exactly alike.
Sometimes you sprint through Indianapolis and walk across a stage at Radio City Music Hall. Sometimes you last deep into the sixth round and languish on the bench until the starter suffers a franchise-altering injury. Sometimes you stock grocery-store shelves and play in the Arena League before getting your shot.
For Mitch Mustain and Chase Rettig, a pair of would-be NFL quarterbacks, the path took them through a junior college 2,000 miles from the league's annual February epicenter. Mustain and Rettig were among more than 250 prospects and dreamers participating in the Los Angeles Regional Combine at Orange Coast College on Saturday.
While one was hoping to launch his NFL career, the other was trying to give his one last jump-start.
Mustain left USC after the 2010 season, ending an interesting but disappointing college career. The former national high school player of the year never got a whiff of the NFL. But there he was on a mild, hazy afternoon, 40 miles southeast of USC, firing footballs to other hopefuls donning numbered gray T-shirts and navy mesh shorts.
"I'm hoping to just get in front of the NFL guys one more time," Mustain said during a break between drills. "Just kind of giving it a last go and see what happens."
Mustain already is a professional football player; after Saturday's workout, he was headed home to the Phoenix area and then on to Texas for the start of training camp with the AFL's San Antonio Talons.
Mustain passed for 632 yards and 11 touchdowns as a backup for the San Jose SaberCats last season -- not bad, but not exactly what he or anyone expected when he was one of the most sought-after recruits in America in the mid-2000s.
Mustain committed to Arkansas and posted an 8-0 record as a freshman for a loaded Razorbacks squad. Mustain then had a falling-out with Coach Houston Nutt, leading to a benching, a transfer and a most circuitous route to the third of the NFL's 10 regional combines.
Mustain never became the starter at USC, losing battles to Mark Sanchez, Aaron Corp and Matt Barkley. Between the end of the 2010 season and USC's pro day, Mustain was arrested for trying to sell his ADHD medicine to an undercover officer. (He avoided charges via a drug-education program and community service.)
Mustain had brief stints with Hamilton of the CFL and Georgia of the AFL. In 2012, he tried out for the Chicago White Sox, who signed him to a minor-league contract. He pitched 23 1/3 innings that summer for the Bristol White Sox and Kannapolis Intimidators before giving football another try.
Mustain also held various civilian jobs -- he currently builds training simulations for firefighters at the Virtual Incident Command Center in Mesa, Ariz. -- and was the subject of a documentary, "The Identity Theft of Mitch Mustain," released in May of last year.
That someone thought Mustain was worthy of a 93-minute film speaks to the lingering fascination about him, especially in his home state of Arkansas. Mustain believes his experiences, on the field and off it, have made him a better quarterback.
"Absolutely," said Mustin, who turns 26 on Thursday. "It's given me a little different perspective and a little different approach to the way I work at it. I feel better prepared now than I have been.
"It's probably better that I didn't go to the league straight out of college. Just the way my mind frame was, my attitude toward the game, the position I was in. I think I'm in a better position now than I was then, and hopefully this will work out."
While at USC, Mustain hoped to become "the next Matt Cassel" -- Trojans backup-turned-NFL pro. Rettig hopes to emulate another former USC player:
Rettig started 46 games for Boston College from 2010-13, becoming the fourth quarterback in school history to pass for more than 7,000 yards. He improved his completion percentage and rating every season, despite playing for five offensive coordinators in four years.
Rettig possesses the requisite size (6-2 1/4, 208) and demeanor to make an NFL roster. Although he's set to participate in Boston College's pro day March 12, Rettig viewed the regional combine as a unique opportunity. The best prospects advance to the Super Regional Combine in Detroit (April 12-13). All 32 teams will send representatives to Ford Field; there's no guarantee that many will attend BC's pro day.
"If you can do it, why not?" said Rettig, 22, who grew up in Southern California. "If you're confident you're going to perform well, it can't hurt you. You never know who's watching. It's just all about getting in with the right team."
Rettig should have little trouble learning a pro playbook after adjusting from one coordinator's system to the next at BC. Starting for four seasons in a major conference also should work to his advantage.
"I played a lot of football," Rettig said. "You grow every year. You remember that situation when it was third-and-7 at Clemson with 100,000 people yelling at you."
It was considerably quieter Saturday, the loudest sounds coming from the horns signifying the start of the next drill. Unlike their high-profile counterparts in Indy -- whose 40s, shuttles and verticals are televised by NFL Network -- the participants in the L.A. Regional Combine worked out in front of a smattering of family and friends, well-wishers watching from behind a fence ringing the south end zone of a small, empty stadium.
The path has to start somewhere.