"(The idea was) once (Denard Robinson) started to move in the pocket, to go get him, allow our guys to have some one on ones," head coach Pat Fitzgerald said.
While Fitzgerald said Northwestern didn't get the kind of production it needed in the package, Mark thought differently.
"Quarterback spy was mainly my goal. To make sure Denard Robinson stayed in the pocket, which he did," Mark said. "I believe in two plays I was in he actually threw two picks. I'm not saying that I caused those two picks, but I think I did my job fairly well."
Mark said he learned early in the week that he might be playing defense, and spent the week practicing with the defense, and going through rushing drills with the linebackers.
"I was excited at first," he said. "I kind of wanted the challenge. I knew Denard Robinson was a great quarterback. He's a running quarterback; he has a lot of speed. Coach bestowed it on me to contain him, so I wanted to take that challenge."
It wasn't all fun and games on defense, however. Though he played cornerback and safety in high school, one thing Mark wasn't prepared for was the size of the offensive linemen he would face. Running into them, he said, felt kind of like running into a brick wall.
"A 6-foot-8 lineman I hadn't really encountered," he said. "Probably outweighs me by about twice me weight, but Coach Fitz was telling me that if a hole opens up, don't just stand there, do something. So I did my best to rush."
Despite the oddity of seeing Mark on defense, his most significant contribution to the Wildcats is with the ball in his hands. He had two carries for 18 yards, one catch for four yards, and a twenty-yard punt return. Mark said he hopes to continue to take on a bigger role in the offense.
"I'm going to try my best, I'm going to give it my all. I just want to be out there," Mark said of trying different positions. "I haven't really played that much in the past, so I'm glad [Fitzgerald] is actually giving me this role right now."
Mark's ever shifting role is a testament to his true athletic ability. When asked if there were NFL players he looked up to or compared himself to, he listed Darren Sproles, Devin Hester, and DeSean Jackson. All three are well known for taking on different roles to utilize impressive speed and mobility.
If he had to choose one position, however, Mark said he would "have to say running back…that's my number one now."