Not only did Sullivan have to spend the coveted day sweating with 100 of his best friends, but he also had to endure their singing.
"I wasn't really expecting that," Sullivan said of the serenade he received from his teammates singing the traditional "Happy Birthday" on the historic event. "I thought we were in trouble when coach Weis called everyone up. That was a nice little surprise."
But considering Sullivan's change in philosophy towards his football career, he likely wouldn't have enjoyed too many adult beverages had he not been in camp.
An unsatisfactory junior season by his standards changed a lot about Sullivan, starting with his diet.
"I came in…..I wasn't responsible in the off season going into that season. It was just one injury after the next," Sullivan explained. "There can be kind of chain reaction with that stuff. One thing starts to get hurt, then you start playing differently and another thing gets affected. I really changed my diet and all my habits in the off season this year. I'm coming in, I'm healthy and I'm feeling great."
Sullivan said he just wasn't doing all the things he needed to do to take care of his body and it affected his play in a bad way.
"I was training right. I wasn't eating right," he recalled. "I wasn't watching what I ate. I wasn't making sure I got enough sleep at night. It was mainly eating. I just got too heavy.
"It wasn't just junk. I wasn't making the healthiest choices possible.
"You just have to make the smart choices. We have a nutritionist on staff, and she's great, but guys know when they're not eating right. That's just part of getting older and getting more experience and growing up and taking responsibility for how you treat your body."
Sullivan isn't the only offensive lineman who's made dramatic improvements in his body over the off season. Every single starting lineman appears to be much trimmer and much stronger heading into this season. Sullivan credits maturity and Irish strength coach Ruben Medoza for the changes in their physiques.
"Everybody is a year older," he said of his fellow offensive linemen. "Everybody eats great. It's a testament to coach Mendoza. We did a lot of hard work in the off season. A lot of lifting, but at the same time we're not just a team that gets bigger by lifting weights, it's about running. We're running hard every day, whether its distance stuff to get your cardiovascular in shape or doing agility to be in shape for short bursts, we're doing it all."
"We can really tell just watching practice and everyone's moving really well," the former USA Today second team All-American said. "Even though guys are heavier, they're leaner than they ever were before. It's really transferring on the field in a positive way."
The senior is now going through the fourth training camp of his college career but he said this year seems to be different.
"It's different every year, but I think we've got a great mesh right now because we have a lot of older guys back, a lot of experienced players," he said. "We do focus on the little things but we don't have to have them repeated all the time. We really know what we're doing out there.
"I think there's just a really positive attitude overall on the team. It's really easy to get down on yourself during camp. If you have a bad play you take it off the field with you and you kind of dwell on it. As you get more experience, you learn how to deal with that. You learn how to forget about that play and focus on the positives.
"Everybody is staying up mentally and emotionally, and the older guys really making that flow throughout the entire team and trying to help the freshmen through some of the bumps that they come along the road. I think it's been a real positive attitude this far into camp."
Sullivan has also accepted a leadership role this year including grooming the next offensive center-to-be, Dan Wenger. "Sully" smiled when asked about Wenger. You can tell he has built up quite a fondness for his young protégé' already even though he didn't say as much.
"I work with Dan quite a bit," Sullivan said with a big smile. "Dan is doing real well right now."
"These kids come in, and they're all really talented athletically," he said of all the freshmen offensive linemen. "They're big kids. They look like veterans. With time they'll get the finer points of the game, but they're all out there working hard."
But what about Weis's comments Wednesday about Sullivan fielding punts?
"Not that day, although I think it's coming up here soon. I've got some skills," he said when asked if he's got his shot fielding punts yet.