That has also become one of the many competitions this spring. All the young players competing to replace guards Bob Morton and Dan Santucci, and left tackle Ryan Harris on the offensive line, try to shout out their calls before Sullivan beats them to it.
"I just try to make sure they're on top of things and keeping one step ahead," Sullivan said. He is the only senior on the entire offensive line, and was already named as the group‘s representative on the team's leadership committee. "They're pretty good at doing that. I think through our meeting time and everything, guys are starting to learn concepts instead of just memorizing what they do on specific plays. And a lot of times they try to beat me to the punch when I try to help them make their calls. There is even competition going on like that, so they're doing a good job."
"With my own calls and my own responsibilities, I've been in the system so long it's kind of like second nature. I can come out of the huddle and have a good feeling what I'm going to do no matter what defense I see or whatever like that. I'm thinking ahead to what calls I can help the younger guys make. But they do a great job of doing that alone because they are thinking a couple steps ahead now too. Everybody is in that mentality, and assignment wise it's been real good."
The 6-foot-4, 290-pound Sullivan could've chose to forego his recently granted fifth year of eligibility and test the NFL waters this coming April, but after helping the Irish to two straight Bowl Championship Series appearances, he felt that he still had things to accomplish in South Bend.
"It just came down to getting all the information that I could from what would happen if I leave and what would happen if I were to come back," the likely preseason All-American explained. "Coming back was the smarter decision when it came down to it, talking to my family and the coaching staff, and I'm happy to be here.
"I would never get the opportunity to come back to college, and I felt like I had some unfinished business here, some personal goals I won't go into. But there were some things including graduating that I wanted to make sure I could do, so coming back was the smarter choice."
Sullivan, who will graduate in May with a marketing degree, making the decision to come back was a huge boost for a team and an offense that loses seven starters from last season.
When Sullivan looks to his right and left at the line of scrimmage he doesn't see the familiar faces of Morton and Santucci lining up next to him, like he had for the past two seasons. In practice, it changes from Olsen, Wenger, Carufel, and Michael Turkovich on every single play. Yet Sullivan is feeling as comfortable as ever with his surroundings.
"Chemistry is important between the center and the guards and the guards and the tackles, and always with the guys you're playing with, but we have a good system, and guys get inserted in and they play well," Sullivan explained. "It's a little different, but once again, it's exciting. It's a chance to work with some younger kids, some strong guys, some guys that really want to be good football players, and if they keep going on the course they're on, they'll end up being really good players."
Sullivan is still having a hard time thinking of himself as the old man on the offensive line. He gets another reminder of how old he is when a teenage quarterback is taking a snap from him.
In his three years as the starter, nobody other than Brady Quinn had taken a snap from Sullivan on Saturdays. Now in practice, four different guys are doing it a day.
"We work on snapping a lot," Sullivan said. "It's not uncomfortable. It's exciting to have new guys in there, and to see what these younger kids can do.
"I know people can't be in there to see it, but it's been a smooth transition so far. We're just working hard and I think we're doing well."
Sullivan is doing well also, in the sense that he is actually healthy and out there participating during the spring. He credits a strong offseason of lifting and working out with strength and conditioning coordinator Ruben Mendoza.
"I don't think I've ever made it through a full spring ball before, knock on wood were only a few days in, but I definitely can tell a difference.
"I was just trying to get in the weight room and get as strong as possible. I ended up improving all my numbers and gaining some weight. I thought it was a successful offseason."
When Sullivan walks to the line of scrimmage this fall with all the new blood around him, he is expecting a successful season as well.