“I have made the decision to retire from football,” Penisini captioned the post. “I’m definitely going to miss my teammates and the coaching staff but I’m glad I got to experience it. I’m happy and excited for whatever life has for me. For my family, friends, teammates, coaches and all the people who supported my dream along the way I appreciate and love you guys. Go Lions.”
Penisini was taken by the Lions in the sixth round of the 2020 NFL Draft. He was initially groomed to be the Lions’ nose tackle under Matt Patricia’s 3-4 defense, but he was a tougher fit in Detroit’s new defense under Aaron Glenn, which includes a more attacking front, rather than a two-gapping scheme that fit Penisini’s skillset better.
Though Penisini didn’t give a reason for his retirement, it’s worth pointing out that the defensive tackle dealt with a pretty serious injury going into the 2021 season. He had built up calcium deposits in his shoulders the size of a softball, per head coach Dan Campbell.
“John Penisini had what looked like softballs in his shoulder that he had repaired after the season after the fact,” Campbell explained. “It just looked like a bunch of calcium deposits that had been in there. You wonder why when you watch the film last year why he’s not using his arm. It’s because he had issues. It’s a credit to him playing through it and all of those things.”
Penisini had not reported to Lions' mandatory minicamp this week, but the Lions were aware of why and clearly gave the opportunity for Penisini to announce his retirement on his terms. Penisini’s NFL career ends with 32 games played, 12 starts and 49 tackles, and one sack.