A defenseman, Johnson was signed as a free agent in 1985 by the Pittsburgh Penguins. In 1989 he was awarded the Aldege "Baz" Bastien Memorial Good Guy Award. He played for the Penguins until he was traded early in the 1990–91 NHL season to the Minnesota North Stars. He followed the North Stars franchise when it moved to Dallas in 1993, and played with them until the trade deadline of the 1993–94 NHL season, when he was dealt to the Washington Capitals. Johnson played for two full seasons with the Capitals before signing with the Phoenix Coyotes as a free agent in 1996, and retired two years later.