At the age of 16 Dan McCarthy played Junior B hockey with the Stratford Cullitons where he recorded 60 points in 36 games. He made the OMJHL's Sudbury Wolves the next season and he played with the club for three seasons. By his final year he had rounded into a good offensive and defensive performer. The main concern from NHL scouts seemed to be their concern over his lack of size, which may have prevented him from being drafted higher.
McCarthy was not selected until the 15th round, 223rd overall by the New York Rangers in the 1978 NHL Amateur Draft. He toiled in the minors for the better part of three years before finally getting the chance to play for the New York Rangers, who had acquired his playing rights. He suited up for five games with New York in 1980-81. Despite the fact he responded with four goals in those five games, he never again played in the NHL although his rights were acquired by the Minnesota North Stars in 1982.
McCarthy played another six years of professional hockey, five in the AHL, but he was unable to draw any further interest from the Rangers or any other NHL team. He retired from hockey after the 1985-86 season after playing with the Springfield Indians.
McCarthy is the founder and president of the Do It Right Foundation and is the general manager of the Connecticut Wolves Junior hockey team. He stepped down as head coach early in 2000-01 after leading the team to two MJHL semifinal appearances in the team's first two years of operation. He continues to run the organization on a day-to-day basis.