Petersen set an NCAA single-game record on March 6, 2015, when he made 87 saves for Notre Dame in a 4-3 five-overtime loss to Massachusetts in a Hockey East playoff game. That came at the end of his freshman season, when he had taken the starting job and begun a streak of 90 consecutive starts.
The Buffalo Sabres had selected the native of Waterloo, Iowa, in the fifth round (No. 129) of the 2013 NHL Draft. But he opted to become a free agent after his junior season at Notre Dame and signed with the Los Angeles Kings on July 1, 2017.