Already a sizable youngster, Austin - or ‘Little Slim' as he was comically nicknamed at the time - wasn't sure he could live up to the precedent set by Leonard Johnson, a linebacker who would have likely made a bigger name for himself had he been a better student and received some notoriety in college.
"People were like, ‘Your uncle…you're going to be a pretty decent ballplayer,'" Austin said during an interview from his school on Monday.
At his first day of football practice, he was matched up against the team's best lineman in middle school.
"We had it out, and everybody was like, ‘Little Slim is going to be nice,'" he said.
By the time he reached Coolidge High School, he was no longer called Little Slim. And now a soon-to-graduate senior at cross-town Ballou, the 6-2 Austin currently tips the scales at 322 pounds.
He says he can easily play at that weight, but he recently received his workout and conditioning program guidelines in the mail, and the UNC coaches told him they would like to see him at 290 this fall.
At Coolidge, Austin met his coach Moses Ware, a former wide receiver with the Minnesota Vikings who played on the same high school team with Johnson at Ballou. After seeing Austin's uncle fail to make it to the next level due to grades, Ware told Austin he would never let that happen to him.
"Everywhere I go, people still talk about my uncle," Austin said.
When Ware first met Austin in the ninth grade, he had heard about him from other coaches, but the knock on him was he wasn't that big. However, Ware thought Austin had plenty of size and wondered what those coaches were talking about.
"When we first had Marvin, you could tell he hadn't grown into an offensive or defensive lineman yet, but he had the uncanny ability to play anywhere," said Ware, who, like Austin, moved from Coolidge to Ballou at the beginning of this school year.
But a growth spurt the following year made it clear to his coaches that Austin was going to be a lineman.
"When I got to school that year, Coach said, ‘You're not going to be a running back,'" Austin said. "I came in at 240 the year before, but at the UVa camp the following summer, I ran a 4.93 and weighed in at 276. I came back for my junior year, and I was like 286; and last season I weighed 290."
Austin's speed and quickness stand out more than his size on the football field, and he's been working out with an AAU track coach.
"I think I have athletic defensive back speed on the line," Austin said. "Most of it is because I have good technique when I run. I'm real relaxed and I pump my arms, and that just came from working hard and staying low. The more I worked at it, the more I started to love it.
"I'm going to be the fastest D-Tackle ever," Austin projected confidently, adding that last year he was clocked at 4.69 seconds over 40 yards and ran a 4.34 pro shuttle during an offseason combine.
For those who don't coach or have never played football, it might seem that size and strength would trump speed on the interior line. Austin has both – a couple days ago he bench pressed 225 pounds 32 times – but he and his coach insist speed and quickness are more desirable traits.
"Size is overrated; but when you have a guy with a combination of both, that's crazy," Ware said.
The laws of physics, especially the formula -- force = mass x acceleration -- lends credence to this stance.
"If you look at guys in the NFL now, they're going smaller because it's more a game about pass rush than it was when it used to be ‘three yards and a cloud of dust,'" Ware said.
"Quickness is everything for a defensive tackle," Austin added. "Speed is good, too, because everything is sideline to sideline. That's how I make my plays, and that's why I think I'm going to be a high draft pick. You get tackles for loss off quickness – off your ability to make somebody miss or get somebody off of you, and then get into the offensive backfield."
Stats can give you a general idea of Austin's ability – 26 tackles for loss and 29 sacks over his final two seasons in high school, plus recording 85 tackles as a senior – but anecdotes drive the point home.
Ware recollects back to a game against St. Albans in which Austin was used as a ‘wedge buster' on the kickoff team. The return man was about 170 pounds, and, Ware says, "must have thought he could step out of the way."
The collision occurred right in front of Ware on the Coolidge sidelines, and the aftermath was reminiscent of the famous NFL moment of Lawrence Taylor standing over Joe Theisman motioning for help.
"I immediately yelled across the field, ‘Coach, you better get over here,'" Ware said.
"The wedge was perfect, too," Austin added. "I remember a lot of plays like that. Players weren't used to being tackled in the open field like that. I remember games where I was just shaking the quarterback and throwing him all sorts of ways."
Stay tuned for Part II, which will delve into Austin's high-profile recruitment…