With just a little bit over a week of spring football remaining, Mattes has again earned his place in the mix, this time for the starting right tackle position.
Mattes thought his chance to start last season was at guard and the season before that at tackle.
"I was hoping so, then there was some movement around and people got moved to different positions and things didn't work out," said Mattes, who has played in 28 games during his career, mostly on special teams. "Hopefully now is my opportunity."
Mattes missed the first two weeks of spring with a foot injury, but upon returning, he has made an impression.
"I think he has gotten better, I think he has improved," offensive line coach John Latina said. "Obviously we didn't have him early in the spring because of an injury, but he has been out there, he has done a nice job. He understands our system, he understands all four positions. Other than center he played all four last year for us and all year at practice. I think that has really helped his knowledge."
"They are two real good players and they are competing well out there," Mattes said.
When Mattes arrived at Notre Dame, he thought he would be competing for a starting spot at defensive end, not right tackle. Then a 240-pound freshman, Mattes didn't appear in a game all season. Shortly there after, Mattes was asked to move to the other side of the ball.
"I didn't see it coming but it ended up being a good opportunity for me," Mattes said. "I probably have had more opportunities to play on the o-line than I would have on the d-line."
Mattes put 30 pounds on his 6-foot-6 frame that first year and since then 20 more. Dedication in the weight room, five meals a day and a heavy protein diet did the trick.
In his first season on the offensive line, Mattes saw action in three games at left tackle. The next season Mattes appeared in one game at tackle. Last year he played in 10 games at guard.
"I think that versatility has helped me with the transitions I've made through different positions on the o-line," Mattes said.
It hasn't been easy. In fact, Mattes finally feels comfortable on the offensive line. It was rough when he was a small 270 pounds and getting pushed around while trying to learn technique. It took nearly four years, but Mattes is now used to the additional weight he is carrying, his footwork has gotten better, and he is "just moving like an offensive lineman."
"I think just confidence and technique," Mattes said when asked about what he has improved upon. "When I first came over my technique was putrid. Throughout practices and with coach Latina, he really emphasizes technique, we do a lot of good technique work and I think that really helped. It has progressively gotten better and now I think my technique is at a place where I can compete with it."
A graduate with a degree in finance, this is Mattes' last chance to accomplish his original goal.
"I came to Notre Dame to play football, to start here. Now this is my opportunity to do so, I just have to take advantage of that now."