LaCoss was drafted by the Cincinnati Reds in the 3rd round of the 1974 amateur draft. He played for the Cincinnati Reds (1978-81), Houston Astros (1982-84), Kansas City Royals (1985), and San Francisco Giants (1986-91). He batted and threw right handed.
LaCoss was an All-Star in 1979.
In 1987 he was 9th in the National League with 13 wins.