[2] Both Marino and his twin brother Paul III weighed over seven pounds, leading doctors to believe one of them would be born with a condition.

[3] After Paul III was born with bowed legs, a doctor at Boston Children's Hospital suggested their parents enroll him in hockey lessons.

Jen and Paul II thus decided to enroll both of their sons in hockey lessons at nearly two years old.

After a single season with the Tri-City Storm in the United States Hockey League (USHL), he committed to a collegiate career with Harvard University of the ECAC.

[14] On July 16, 2022, Marino was traded by the Penguins to the New Jersey Devils in return for Ty Smith and a 2023 third-round pick.