Originally chosen by the Buffalo Sabres in the 2013 NHL entry draft, Cal Peterson was deciding instead to play out his college career at Notre Dame and instead opt for free agency. His decision was rewarded when he signed with the Los Angeles Kings on July 1, 2017.

It was while playing for the Fighting Irish that Petersen would set an NCAA record. In a Hockey East playoff game against Massachusetts on March 6, 2015 that would stretch into a fifth overtime period, Peterson turned aside a record 87 shots. It wasn’t enough, however. Notre Dame lost the game 4-3. 

Petersen started 90 consecutive games in the Fighting Irish net during his college days. He was picked to the Hockey East All-Rookie and All-Academic Teams in 2015 and was a Hockey East All-Star selection in 2017.

Turning pro in 2017, he began his playing career with the AHL’s Ontario Reign, top farm club of the Kings. He was picked to play in the AHL All-Star Classic in 2018. During the 2018-19 season, Kings goalie Jack Campbell was injured and Petersen was recalled from Ontario on November 12, 2018. He saw his first NHL action the next night in relief of Jonathan Quick. Petersen stopped 15 of 16 shots he faced in a game against the Toronto Maple Leafs. 

Petersen would make his first NHL start on November 16, 2018. Blocking 34 shots, he earned a 2-1 victory over the Chicago Blackhawks. When his stint with the Kings came to an end, Petersen had fashioned a 5-4-1 slate with a 2.61 goals-against average and .924 save percentage. At season’s end, the Kings rewarded him with a three-year contract.

He’d enjoy a strong campaign with Ontario in 2019-20. Petersen would earn selection to play in the 2020 AHL All-Star Classic. His big break would come on February 5, 2020. The Kings traded Campbell to the Leafs, and Petersen was recalled to replace him as Quick’s understudy. He’d post a .922 save percentage over eight NHL appearances that season.

Petersen became a capable NHL backup with LA. He started 32 games and posted a .911 save percentage in 2020-21. The next season, he’d make 35 starts for the Kings, but his save percentage dipped to .889.

His struggles continued to start the 2022-23 campaign. Sporting a 3.75 GAA and .868 save percentage through 10 games, Petersen was placed on NHL waivers. He would ultimately be moved to the Philadelphia Flyers as part of a three-team deal that included the Columbus Blue Jackets. 

Petersen saw action in five games for the Flyers in 2023-24, going 2-2 with a 3.90 GAA and .864 save percentage. 

He’s twice represented USA Hockey at the IIHF World Championship, in 2021 and 2023. The 2021 tourney saw the USA win the bronze medal and Petersen be named the tournament’s top goaltender.