"It was a dream come true," Mabin said of his signing with Baltimore. "Since I was little, that was always my dream, playing in the NFL and getting that opportunity."
The last time Mabin suited up in pads, he suffered a torn pectoral in Northwestern's Senior Day game with Michigan State. Mabin had surgery in late November, and was forced to miss NU's appearance in the Meineke Car Care Bowl of Texas.
Mabin worked hard in the months following his injury and finished his recovery in April, well ahead of doctor's projected schedule.
When Mabin suited up for his tryout at Baltimore's rookie mini-camp, it was his first organized football activity since his injury.
"At first, I was a little rusty, but it got back pretty quickly," Mabin said.
Mabin's was given no guarantees with Baltimore; he had an uphill climb to land a spot on the team.
"Going into it, I knew I had to beat out some people to make the squad," said Mabin. "I just had that mentality going into it that I was going to work hard."
When news of Mabin's signing became official, he received an outpouring of support via phone, Facebook and Twitter.
"It was awesome, it was a great feeling knowing I had support from my hometown, friends at college, friends, family, and people I didn't even know," said Mabin. "That was reassuring, knowing it's bigger than me, people are supporting me. I'm just blessed to be here, to make it, and it's a good feeling."
Mabin is now a Raven, but faces a new challenge: mastering Baltimore's complex playbook.
Baltimore's storied defense has numerous complex schemes, which means Mabin must learn the proper checks of the secondary.
"Just seeing how they go about their work day in and day out, not taking a play off, running to the ball," Mabin said. "That's what they do and what they expect. They set the bar very, very high."
Mabin is participating in Baltimore's OTAs, working hard in the team's secondary. He is taking advantage of his opportunity, looking to stay a Raven.
"I still could get cut, anything could happen," he said. "Right now, I've got to grind. It was a dream come true (to be signed), but I have to stay focused and keep on working."