A left-handed batter who threw right-handed, Sullivan stood 6" (183 cm) tall and weighed 195 pounds (89 kg) as an active player. After graduating from Bernards High School, Sullivan signed with the Detroit Tigers in 1959 and made his debut with them in the waning days of the 1963 season. He played in five major league seasons with Detroit (1963-1965), the New York Mets (1967) and Philadelphia Phillies (1968), appearing in 116 games, with 59 hits in 259 at bats, batting.228 with two home runs and 18 runs batted in.
His only substantial terms of MLB service were as a reserve catcher for the 1965 Tigers and 1967 Mets, for whom he played his only full season in MLB. He played eight years at the Triple-A level
Sullivan began managing in minor league baseball in 1973 in the Kansas City Royals" farm system. During six seasons, he rose from Rookie ball to Triple-A, winning four league championships and compiling a stellar.601 winning percentage (434 victories and 288 defeats).
His only under.500 club, the 1978 Omaha Royals, who finished 66–69, nevertheless topped their division and defeated the Indianapolis Indians for the American Association championship. In 1979, Sullivan began a 15-year run as a Major League coach, serving with the Royals (1979), Atlanta Braves (1980-1981) and Toronto Blue Jays (1982-1993).
He was brought to Toronto by Bobby Cox after Cox" first term as Braves" manager, and remained with the club under Cox successors Jimy Williams and Cito Gaston, coaching on the Blue Jays" 1992 and 1993 World Series championship teams.
His final game was Game 6 of the 1993 World Series, and his retirement was announced at the Blue Jays" championship celebration. Sullivan was asked to unveil the 1993 World Series Championship banner at the end of festivities.