Arnaldo Juan Contreras
- Bats Both, Throws Right
- Height 6' 2", Weight 193 lb.
- High School Tampa Catholic High School
- Debut May 23, 1980
- Final Game October 1, 1980
- Born September 19, 1951 in Tampa, FL USA
Nardi Contreras pitched in 8 games with the Chicago White Sox in 1980. He did not record a decision and the Sox lost every game he appeared in. His best outing was on October 1st when he pitched 1 2/3 innings against the Oakland A's, giving up no hits, no runs and striking out 2. It was his only outing in which he did not give up a hit. He gave up one home run in his career; the batter was Jim Anderson of the Seattle Mariners.
He began his coaching career as the pitching coach of the AA Glens Falls White Sox in 1982. After three years in Glens Falls he moved up to the AAA Buffalo Bisons for the 1985 season. In 1986 he began a two-year stint with the GCL Braves. He moved on to the Montreal Expos organization becoming the pitching coach for AA Jacksonville Expos from 1988-1990.