He played for the White Sox (1970), California Angels (1971–1973), Milwaukee Brewers (1976), and Kansas City Royals (1978).

He was somewhat error-prone behind the plate during sporadic playing time at the major league level, committing 20 errors in just 136 games for a .970 fielding percentage.

Kusnyer was involved in a nine-player transaction when he was sent along with Steve Barber, Clyde Wright, Ken Berry and cash from the Angels to the Brewers for Ellie Rodríguez, Ollie Brown, Joe Lahoud, Skip Lockwood and Gary Ryerson on October 23, 1973.

[1] After his playing career, he eventually found his way back to the White Sox as the bullpen coach, where he served for 19 years (1980–87, 1997–2007).

[2] He was a longtime member of Tony La Russa's coaching staffs in both cities.