Education
O'Brien attended Bishop Barry High School (St Petersburg, Florida) and Florida State University.
O'Brien attended Bishop Barry High School (St Petersburg, Florida) and Florida State University.
O'Brien played for the St. Louis Cardinals in 1978 and 1979. He was drafted by the Cleveland Indians and Chicago White Sox in the 1972 and 1975 amateur drafts, but did not sign with either team. However, in 1976, he was drafted again and signed with the Cardinals.
He pitched in the Cardinals' farm system from 1976–1978 culminating with the Springfield Redbirds, their AAA affiliate in the American Association. O'Brien made his MLB debut in the nightcap of a double-header against the Philadelphia Phillies pitching 1 inning but surrendering 3 runs on 5 hits in the Phillies' 10–2 victory on September 4, 1978. His first decision, a loss, came 4 days later when the Cardinals lost, 2–1, to the Phillies at Veterans Stadium.
He pitched 8 innings of 1-run baseball but surrendered 2 hits before inducing a groundout to start the bottom of the 9th inning. Buddy Schultz relieved him but gave up the game-winning single 1 out later. O'Brien opened the 1979 season back with Springfield before joining the Cardinals in early August.
His only victory came on August 31, 1979, when he pitched 2 innings of scoreless relief in a 41⁄2 hour, 15 inning marathon against the San Diego Padres at San Diego Stadium. After the 1979 season, the Seattle Mariners purchased O'Brien's contract. However, he was released shortly before the 1980 season.
He found work with the Richmond Braves, the AAA affiliate of the Atlanta Braves in 1980 and the beginning of the 1981 season. He finished the 1981 season with the Columbus Astros, the Houston Astros' AA affiliate in the Southern League.