During three seasons in the OHL with the Owen Sound Attack and the Barrie Colts, Dotchin earned 18 goals and 59 assist for 77 points, along with 279 penalty minutes, in 193 games. Dotchin was drafted by the Owen Sound Attack in the 4th round, 70th overall, in the 2010 OHL Draft. While with the Attack, Dotchin was drafted 161st overall by the Tampa Bay Lightning in the 2012 NHL Entry Draft. After playing in 38 games for the Attack during the 2012–13 season, Dotchin was traded to the Barrie Colts in exchange for draft picks.
Professional
On April 19, 2014, Dotchin signalled the beginning of his professional career in signing a three-year entry-level contract with the Lightning. On January 17, 2017, the Tampa Bay Lightning recalled Dotchin from the American Hockey League, and he made his NHL debut 4 days later against the Arizona Coyotes at Gila River Arena. On January 31, 2017, Dotchin recorded his first career NHL point and assist at Amalie Arena. On April 4, 2017, Dotchin was involved in an incident with Boston BruinsBrad Marchand. With the two players battling for position in front Lightning goaltender Andrei Vasilevskiy, Dotchin delivered a cross-check to Marchand, who responded by spearing Dotchin in the groin. Dotchin did not return to the game, while Marchand received a 5-minute major penalty for spearing and a game misconduct. Dotchin was not suspended for the cross-check, but Marchand was suspended two games for the spear. After being returned to the Crunch at the end of the regular season, Dotchin was involved in another incident with Toronto Marlies forward Frédérik Gauthier, where he received a 5-minute major penalty for interference and a game misconduct. He later received a 3-game suspension from the AHL. On July 5, 2017, Dotchin signed a two-year, one-way contract extension with the Lightning valued at $1.625 million. On November 8, 2017, Dotchin recorded his first career NHL goal, which came in a 5-1 Lightning win over the San Jose Sharks at the SAP Center. On September 4, 2018, Dotchin was placed on unconditional waivers for contract termination by the Tampa Bay Lightning, who cited a "material breach of contract." Dotchin cleared waivers the next day. According to sports journalistElliotte Friedman while on a Sportsnet650 radio talk show, Dotchin had reportedly showed up to training camp "with 25% body fat" and "was extremely out of shape". Bob McKenzie, on TSN 1050 Toronto's First Up radio show, stated that Dotchin "was a good 30 to 35 pounds above his playing weight". On October 17, 2018, Dotchin was signed to a one-year, $800,000 contract by the Anaheim Ducks. After clearing waivers, Dotchin was assigned to continue to improve his conditioning with AHL affiliate, the San Diego Gulls. During the 2018–19 season, Dotchin was later recalled to the Ducks and registered 1 assist in 20 games. On June 25, 2019, Dotchin was not tendered a qualifying offer by the Ducks, releasing him to free agency. On July 1, 2019, Dotchin agreed to a one-year, two-way contract with the St. Louis Blues.
