It is why Rutgers recruited him to play defensive end.
But after watching him practice for more than a year, coach Greg Schiano thought he was a perfect fit for defensive tackle, and the switch was made.
"He's a natural inside 3-technique," Schiano said. "He's 250. That guy will be 290 when he leaves here. He's got instincts and he's got great body control. He's a little bit like Gumby. He can contort his body. He's getting blocked and he can (turn his shoulder) and slipoff a block."
Larrow, a red-shirt freshman, excelled in practice the last month. Coupled with the tragic spinal cord injury suffered by junior Eric LeGrand, it is why Larrow is playing markedly more, and will be a key figure in today's game against Cincinnati (7:30 p.m.) at Nippert Field.
"Mike's a young guy, but he's extremely eager to learn," Rutgers senior defensive tackle Charlie Noonan said. "He's very talented athletically. It's really coming along with Mike. He started a little slower, but it's starting to click for Mike. It's exciting because he can be as good as he wants to be."
Larrow had a breakout game last week against Syracuse. He made four tackles, including his first career sack, after entering the day with three career tackles.
It took a halfway through his second college season to gain marked playing time, which is what he was told when the switch was made. He is rotating in with defensive tackles Scott Vallon and Noonan.
"I was told they would need me in the second half of the season," Larrow said. "I've played with a better pad level, and (better) understand the defense," Larrow said. "If I didn't play before, it's because I wasn't ready. I've just been improving throughout the season. I'm not where I want to be. I'm just better."
He is also much wiser than a year ago, when he quickly learned he wasn't ready to play.
"I came in here with an open mind, and I came here because I trusted the coaching staff and I know they know what they were doing," he said. "If I did play that was good. If I didn't play, I understand why I didn't. I looked at the playbook and my head was spinning. I realized it was a lot tougher than high school."
Tops on Larrow's list when it comes to his offseason development is gaining weight.
He looks like a defensive end now, but plans to reshape his body in the offseason under the guidance of strength and conditioning coach Jay Butler.
"I definitely need to get a little more (weight on)," Larrow said. "I'm just eating and trying to gain as much weight as possible until J.B. tells me to stop."
There are a few other things Larrow needs to focus heavily on in the offseason.
"Probably striking more (with his hands), probably a lower pad level," he said. "That's about it."
Moving inside isn't totally strange. Larrow switched between defensive end and defensive tackle at Union (N.J.) High.
However, it is a much bigger game in the middle of the line of scrimmage.
"(The biggest thing) is probably just the size difference between the people you play, and the double teams," Larrow said. "Another thing is instead of having a tackle and a tight end double team you, it's a tackle and a guard. It's just two bigger bodies."