Lethemon, 26, spent the majority of the 2022-23 season with the ECHL's Toledo Walleye, winning the Nick Vitucci Goaltender of the Year Award as the league's top netminder after posting an 18-1-3 record with a 1.99 goals-against average, a 0.930 save percentage and four shutouts in 26 appearances. The 6-foot-3, 190-pound goaltender also held a 4-2 record with a 2.64 goals-against average and a 0.917 save percentage in seven postseason contests to help the Walleye reach the Western Conference Finals. Additionally, Lethemon played in nine games with the American Hockey League's Grand Rapids Griffins in 2022-23, going 1-6-2 with a 3.88 goals-against average and an 0.878 save percentage. Lethemon split the 2021-22 campaign between the AHL's Ontario Reign and the ECHL's Greenville Swamp Rabbits, holding a 2-0-0 mark with a 2.01 goals-against average and a 0.931 save percentage in two appearances with the Reign, while building a 15-11-6 record with a 2.69 goals-against average, a 0.911 save percentage and two shutouts in 32 games with the Swamp Rabbits. In all, Lethemon has accumulated a 46-17-14 record with a 2.49 goals-against average, a 0.914 save percentage and seven shutouts in 83 ECHL appearances between the Swamp Rabbits and Walleye since 2020-21.