It also was a symbol of how hard the true freshman has worked in a program he grew up admiring, a program he almost didn't get a chance to compete in.
"It's been baby steps every day and it really has hit home for me," Costigan said. "I am trying to take advantage of every opportunity I am given. Strength only gets you so far at this level."
Costigan was one of the more intriguing prospects in the 2010 recruiting class out of Muskego High School. A big body that could play either offense or defense, the final decision, contrary to belief, didn't come down to a wrestling match between Offensive Line and Recruiting Coach Bob Bostad and Defensive Line Coach Charlie Partridge, especially since Bostad fought so vigorously to get Costigan a full offer.
"I just really felt he was a big that embodied what we are about and someone we needed in the program," Bostad said.
To make matters more complicated, Wisconsin was unable to get a real sense of what Costigan could do until he finally stepped on campus, in part because a high ankle sprain suffered last summer prevented him from competing during the camp circuit.
"I thought after I sprained my ankle I had missed my chance to play here," Costigan said. "As things went along and things filled up, I didn't think I would be a Badger. It was definitely an up-hill battle for me."
Costigan's raw abilities were enough to get Bostad and Partridge to come out and watch him play. Just his luck, Costigan played on a team that finished 1-8 and he didn't play much defensive line in wet, soggy conditions.
"It was a really tough evaluation because the night he played, he played almost exclusively offensive line," Partridge said. "I think he only played some on defense that night, partly because I was there to be quiet honest. He did some nice things, but you can tell that he didn't spend a lot of time on defense."
Costigan did receive a grayshirt offer in December, meaning he would not have joined the football team until January 2011. But after a player left the program, a scholarship opened up and, due to a variety of factors, Costigan was given a full offer.
The first reason was Bostad, who had become so impressed with Costigan during the recruiting process that he pushed to use that open scholarship to bring him in. The other reason was Head Coach Bret Bielema recognizing that every time he saw Costigan, he appeared to be 10 pounds heavier.
"When he came on his official visit, he was up to like 275," Bielema said. "I was like, ‘Forget this, we're going to take this kid.'"
But with Wisconsin lacking depth at defensive tackle, Bielema decided to move Costigan to the defensive line, hoping to give that line an energy boost. Costigan has responded by increasing his 6-foot-4 frame to 296 pounds, and having many of his teammates and Strength and Conditioning Coach Ben Herbert call him one of the strongest freshmen ever in the program.
"In terms of some tradition lifts, he was probably the strongest I have seen in terms of benching and squatting," Herbert said of Costigan, who admits to working out starting at a young age. "Now there are some things and some lifts that other guys are better than him at, but in terms of traditional lifts, you could tell that he was exposed to and trained to in high school that gave him some very physical tools."
The same could be said about true freshman Beau Allen, who, like Costigan, has enamored the coaching staff with his physical tools and characteristics. Throughout camp, the two have been rotating in at the second-team defensive tackle position.
"It's awesome and we really push each other," Costigan said of Allen. "He's big, and I'm big. We're going to work together for the next four years and it's going to be really competitive. He's a good friend and it's going to be a good thing. We're both freshmen and it's nice to have to someone to relate to with some of the same issues we're having."
With four defensive tackle starters having graduated and injuries occurring in front of him, Costigan is expected to see his work load increase over the next week. Not too bad for a guy that thought he would be working at a part-time job this summer and waiting patiently for his chance to enroll.
"This is honestly the best possible thing that could happen," Costigan said. "There's a huge jump in competition from high school to the college level. It's crazy, but the more reps I get, it's going to help me get better."