The 18-year-old, who just graduated this past spring, improved so much that he became a two-sport athlete, and to top it off, a state champion in basketball.
For those reasons Clark is the 2006-07 Standard Democrat Male Athlete of the Year, marking the third straight year a Charleston athlete has received the honor.
"I always thought I could become a good athlete," said Clark, a 6-foot-4, 195-pouder. "I knew I had the potential. That's what everybody always told me so I just kept working hard."
As a freshman, Clark wasn't even supposed to be the best athlete in his own class at Charleston.
"Starting out his freshman year of our three basketball players, Shawn, Jamarcus and Justin, (Clark) was No. 3 at that time," admitted Charleston coach Danny Farmer. "He just kept getting better, improving his game and becoming a better player. By his senior he was a different player. It came at the right time with the injury to Jamarcus. He really stepped his game up. He's unbelievable. He's a great two-sport athlete."
Although Clark may be most remembered as the smooth-shooting 3-point marksman for the Bluejays' 2007 state title basketball team, his first love is on the football field where he was a member of a district championship team as a sophomore.
He was a two-time all-state defensive back and a talented wide receiver before making a necessary switch to quarterback last fall.
Despite never playing the position, he overcame an early ankle injury and threw for 586 yards with five touchdowns while providing the Bluejays with a dangerous weapon running the option.
"On defense he was just as good if not better. He had great instincts as a defensive back and was just a great athlete back there."
Although Clark's senior year in football was an overall disappointment after a rash of injuries decimated the team, he still banked his future in the sport, signing with Murray State in February.
"I like basketball a lot, but football is my favorite sport," said Clark. "I've got a family history in football. There's just something about football that I like the best.
"I'm going to try to compete and get early playing time. I've got to work hard, listen to the coaches, and hopefully I'll be playing this year."
One of the injuries was to Williams, a broken leg that sidelined him for the early part of the basketball season.
That made Clark even more valuable to Farmer's team.
And Clark's experience in leading the football team at quarterback, only helped prepare him for the challenge ahead.
"I think playing quarterback and being the leader in football helped him a lot in basketball," said Farmer. "Going into the season it was a question mark to me, especially after Jamarcus' injury. I really needed him and Shawn to pick it up. Then Shawn got hurt also, and Justin picked it up even more and kept us right on track. I just saw some things that I had never seen before. It was just all of a sudden."
Williams and Sherrell both eventually returned to the court, but Clark continued to carry the team.
He always had the deadly jump-shot, but his overall game improved a great deal as well.
"I believe being a football player made me a better basketball player -- making me more physical and stronger on the court," said Clark. "In basketball it helped me in football too -- just competing and winning helps you in any sport."
Clark, long considered a role player in basketball, was the team's leader all the way to the state championship, the team's first in 11 years. He led the team in scoring at 17 points per game and added five rebounds per game. He drained 77 3-pointers at a 36 percent clip.
"(Clark) was very difficult to guard, but he was more than just a shooter," said Sikeston head basketball coach Gregg Holifield. "He could defend and he could rebound. When you're as athletic as he is, where he could pull up and shoot right over people, that made him very difficult to defend."
He was named first-team all-state for his efforts, along with teammate Sherrell. Williams, despite being hobbled with the leg injury, still secured a second team selection.
It was the perfect ending.
"I wanted that state title -- that's the highlight of my career," said Clark, who was also a member of three other basketball final four teams.
Now it's off to college for Clark, who, in addition to his athletic prowess, was strong in the classroom as well, posting a 3.6 grade point average.
"My best advice I ever got was academics comes first, even before sports," said Clark. "I have NFL dreams, but I also want to get my college degree. I'm going to try to do both all in one shot."
It's that kind of attitude that gives Farmer the impression that Clark will fit right in at Murray State.
"I think he will succeed -- I think he's one of those athletes that will play up to his competition," said Farmer. "If he's playing with some real good guys I think he'll play right along with them."
Football Player of the Year: Josh Stevens - Dexter
Basketball Player of the Year: Justin Clark - Charleston
Baseball Player of the Year: Drew Pixley - Dexter
Wrestling: Gavilian Bland - Sikeston
Golf: Dakota Trevino - Sikeston
Tennis: Sam Zhao - Sikeston