While serving in the U.S. Navy, he befriended a fellow officer, Jim Britt, the radio play-by-play announcer for the Red Sox and Boston's National League team, the Braves.

Tom Yawkey, the Red Sox' owner and club president since 1933, had historically hired famous former players to serve as his general manager, and through 1960 his three GMs—Eddie Collins, Joe Cronin and Bucky Harris—were all current or future members of the Baseball Hall of Fame; Collins and Cronin were standout players, while Harris had won three American League pennants and two World Series as a field manager.

The New York Times reported on October 1, 1960, that Higgins would assume responsibility for all player personnel decisions, Major and minor league, in the Boston organization, a role typically performed by a general manager.

During the early 1960s, Boston overhauled its farm system and scouting operation and was beginning to produce outstanding talent, but the big league Red Sox continued to struggle and attendance dwindled.

Still seen as inexperienced in baseball operations and talent evaluation, O'Connell initially shared power with vice president, player personnel Haywood Sullivan, a former Major League catcher and manager recruited from the Kansas City Athletics in November 1965.

He promoted Dick Williams to manager and traded for players such as pitcher Gary Bell, infielder Jerry Adair and catcher Elston Howard.

The Red Sox posted winning seasons from 1968 to 1974 and continued to rank among the AL leaders in home attendance, but could not match the success of the league's dominant teams of the era, the Detroit Tigers, Baltimore Orioles and Oakland Athletics.

Tom Yawkey had developed a close friendship with Haywood Sullivan—by 1975 playing a reduced role for the Red Sox as director of amateur scouting—but trusted O'Connell to be his top baseball and business executive.

She criticized O'Connell's player transactions, his willingness to negotiate with (and ultimately sign to new contracts) potential free agents Fisk, Lynn and Burleson, his attempted big-money purchase of Rollie Fingers and Joe Rudi from the Oakland A's in June 1976 (vetoed within hours by Commissioner of Baseball Bowie Kuhn), and his signing of free agent relief pitcher Bill Campbell.