[4] Following his rookie year at Bemidji State, where he led defencemen in scoring, Whitecloud was invited to the Los Angeles Kings development camp before the 2017–18 NHL season.[11] Although the Golden Knights qualified for the 2018 Stanley Cup playoffs, Whitecloud was ineligible to be on the roster since he was not on the team's reserve list by the trade deadline.[13] Late in the 2019–20 season, Whitecloud established himself with Vegas Golden Knights and he and teammate Nick Holden were one of the best duos in the playoffs in terms of defense and possession.[17] The Golden Knights reached the 2023 Stanley Cup Finals, with Whitecloud one of two indigenous players in the series, alongside Mohawk defenceman Brandon Montour of the opposing Florida Panthers.During the 2018 offseason, Whitecloud volunteered as a guest instructor at Micheal Ferland's Hockey School in Brandon, Manitoba, alongside Brigette Lacquette, Harley Garrioch, Jens Meilleur, Ryan Pulock, Tyler Plante, Shaq Merasty, Josh Elmes, and Joel Edmundson.