He was a left-handed pitcher and first baseman who played in the farm system of the Chicago Cubs for three seasons. In 1988, he pitched for the Charleston Wheelers and the Winston-Salem Spirits. He played for the Peoria Chiefs in 1989 and 1990.

From 1984 to 1987, Duenas was a pitcher for the University of Southern Illinois at Edwardsville, setting several school records. He was named an All-American in 1985 when he helped the SIUE Cougars advance to the College World Series. That year, he won ten games and had 95 strikeouts. He also hit 15 home runs which remains a single season school record. His 13 doubles and 55 RBIs led the team that season. Duenas was inducted into the SIUE Athletics Hall of Fame in 2007.

In 1985, he pitched for Edwardsville in the Central Illinois Collegiate League. He was with the Edwardsville Traders in 1989 and 1990. He played in the Mon-Clair League for Millstadt in 1986, Vanzo's in 1987, Bon-Aire in 1991 and 1992, and Granite City in 1993. He participated in numerous Valmeyer tournaments.

In 1987, he joined the Sotolar Pointers in the CYC Senior Major League, helping his team advance to the
NBC Tournament in Wichita, Kansas.

In the early 1980s, Duenas played for Althoff High School in Belleville. He coached baseball at SIU-Edwardsville, and then became a successful high school baseball coach. He coached at Edwardsville High School, Belleville West High School, Springfield Sacred Heart-Griffin High School, and Pawnee High School in Pawnee, Illinois. Duenas is currently the head baseball coach at Richland County High School in Olney, Ilinois. He spent four years as the assistant coach and has been the head coach for three years.

Duenas also coached little league baseball teams, winning an Illinois state championship.