Following the Dodgers' move to Los Angeles, Newcombe got off to an 0–6 start in 1958 before being traded to the Cincinnati Reds for Steve Bilko, Johnny Klippstein, and two players to be named later during the season. He posted a record of 24–21 with Cincinnati until his contract was sold to Cleveland in mid-1960. He finished with a 2–3 mark in Cleveland before being released to end his major league career. Newcombe acknowledged that alcoholism played a significant role in the decline of his career.
