In 1972 he trialled and was graded with the Penrith Panthers in the Sydney competition player 17 games that season in the 3rd grade side coach by Tom Wilson.
In 1973 he was a member of Penrith's under 23's side which qualified for the play-offs side losing to Balmain Tigers in the eliminating semi final.
In 1974 Klein made his initial first grade appearance against North Sydney at Penrith Park, losing 28–23 in a close encounter. Over the next four seasons, he played a total of 30 games in the top side which was affected by injuries and a loss of form.[1]
At the end of the 1977 season, Klein signed an agreement to Captain-coach Bathurst St Patricks in the Group 10 CRL competition with limited success. He played with St Pats for 3 seasons (1978–81) scoring over 60 tries for the club. Retiring halfway through the 1981 seasons due to injuries.
In 1983, he was transferred in his employment (State Bank) to Quirindi where he came out of retirement and played with "Grasshoppers" for 3 seasons (1983–85). He was appointed Captain-coach for the 1985 season.
In 1986, following another transfer in his employment to Sydney at the end of the '85 season, Klein played for 2 seasons with the Brothers club in the North Sydney competition winning the "A" grade division in 1986. Appointed Captain-coach for the 1987 season he was forced to retired midway through the season due to further injuries.
Klein is the father of NRL referee Ashley Klein.
