Because Roberts played for the Bruins under these emergency circumstances, he lost his amateur status, and was unable to return his amateur team - the Boston AA Unicorns. Instead Moe caught on in the Canadian-American professional league, first with the New Haven Eagles and later the Philadelphia Arrows.
After nearly 6 full seasons in the Can-Am league, Roberts finally returned to the NHL on March 10, 1932. The New York Americans promoted Moe in order to replace the injured Roy "Shrimp" Worters. He played extremely well in that game as the Americans knocked off their cross town rivals the New York Rangers 5-1.
Moe's impression that game earned him his first legitimate NHL shot the following season. Although he spent the vast majority of the season with the Cleveland Indians of the IAHL, he got into 6 games with the struggling Americans. This time he was thrown into the deep water of the NHL, and he surfaced with a less than remarkable 1-4 record with a 4.46 GAA.
Moe was banished to the minor leagues until his retirement in 1946. Most of that time was spent in the city of Cleveland, first with the Indians/Falcons of the IAHL and later with the strong AHL Barons. Roberts was a key player in the Baron's success. He was particularly strong in 1938-39, when he led the Barons to the AHL championship with 4 playoff shutouts (in just 9 games) and a 1.13 GAA, and 1939-40, when he led the league with 5 shutouts and 2.24 GAA.
Roberts played until 1942 when he retired. He came out of retirement 3 years later to play with the Washington Lions of the EHL, but retired at the conclusion of that 1945-46 season.
The Chicago Blackhawks hired Roberts as a trainer. In addition to his duties in the dressing room, Roberts often donned the pads during practice in order to give players some shooting practice. This helped kept Roberts sharp and doing what he loved to do.
Roberts made a very unexpected return to the NHL on November 25, 1951, 18 years after his last NHL game. Starting goalie Harry Lumley became injured during the game and was unable to continue the game. Roberts soon found himself between the pipes again, playing one shutout period against the Detroit Red Wings.
An interesting side note: Roberts was just shy of 46 years of age when he played in that game, making him the oldest player in National Hockey League History. That record was of course broken by Gordie Howe, who played at the age of 52.