Mielnik came back every season and continued to work hard despite the damage the sport was doing to his body.
"I can't think of a time when he didn't take his setbacks in stride," Mielnik's father Pete Sr. said. "He never moped, and he never felt sorry for himself. Physically, it's been very hard for him, but he never talked about giving up."
Mielnik's ability to shake off the disappointments and stay committed to wrestling has garnered him a lot of praise from his coaches and teammates.
"He's just so persistent and determined," Penn State wrestling coach Troy Sunderland said. "A lot of people would've given up and moved on after all he's been through, but he's made the commitment, and he's kept fighting. He's got a lot of character and a lot of heart."
Mielnik injured the knee again earlier this season but he has been able to tolerate the pain, postponing knee surgery until after nationals. He's continued to wrestle through his redshirt junior campaign and it's paid off for him.
He had to fight fifth-year senior Dave Heckard for the starting spot at 197 pounds. After splitting time with Heckard most of the season, Mielnik finally won the job in their final wrestle off, and was on the starting squad at Big Tens.
Mielnik wasn't sure if he would ever wrestle after the tournament, however. A criminal justice major, Mielnik has an internship lined up for the fall semester with the Bureau of Alcohol, Tobacco, and Firearms. The internship would run into the beginning of the wrestling season, and he considered not returning to the squad. A lot of that decision would hinge on how he did at the Big Ten Tournament.
After his consolation match against No. 4 seed Joe DeGain from Michigan, he was seriously considering not coming back.
DeGain won a close match over Mielnik with a last second takedown, which forced Mielnik into a do-or-die seventh place match the next day.
He was visibly distraught after the loss, struggling to keep his face from giving into his emotions.
Instead of allowing the defeat to hold him back in his seventh-place match, he went at that match as hard as he had any this season.
Mielnik wasted little time assuring himself that he would wrestle once more, downing Nik Fekete of Michigan State in just 59 seconds. The win garnered him a spot at this weekend's NCAA tournament in Iowa City, Iowa.
"I was pretty crushed after last night," Mielnik said after his victory. "I was really tired, and really hurt, and I didn't think there was any chance I was going to pull this off. But I went back to the hotel, regrouped, and realized that this may be my last chance, and it's now or never."
Mielnik has since decided to return to the team after his internship is over in December, which will ease a lot of the tension off of him at nationals.
"Knowing I will have another chance next year will really take some pressure off this week," he said. "If I would've went 0-3, I would've been really crushed."
Though his love for the sport is strong enough to bring him back, Mielnik knows it will soon be time to move on permanently. As the injuries have taken their toll on his body, he has realized the necessity of focusing on academics.
"After the second knee surgery I realized all of this could be gone pretty quick," he said.
Since that surgery, Mielnik has made the Dean's List five consecutive times, and will likely be on it again this semester.
"He's gotten really serious about his grades," Pete Sr. said. "He has just astounded us. We're tickled to death."
Mielnik's struggles through adversity and success off the mat have made him a great role model for the young Penn State wrestlers. He has also become one of the more vocal leaders of the veterans on the squad.
"Pete's a great leader," said junior heavyweight Bob Jones. "He's somebody who stands up for his beliefs and doesn't care what other people think. He's a straight shooter, and he tells it like it is."
After qualifying for nationals, Mielnik thinks that when the time comes, he will be able to leave the sport.
"I think I'll be able to walk away," he said. "When I first got here, and I was really getting beat up as a freshman, my goals were to wrestle all four years, and to qualify for nationals. I think I'll be happy with my career no matter what."
And considering the commitment he's shown off the mat, he will likely be happy with his professional career as well.