 During the 2004–05 NHL lockout season, Tollefsen had signed for the Blue Jackets, but spent most of the season with the Syracuse Crunch of the American Hockey League (AHL), but also had a short trip to the ECHL where he played for the Dayton Bombers.For the 2005–06 season he started the season in the AHL, but on November 23, he got his NHL debut in a 4–2 loss against the Phoenix Coyotes.He played an additional four games for the Blue Jackets, with two penalty minutes, before he was sent down to Syracuse again, where he spent the rest of the season.