equipment from Derek Jeter's locker in the Legends Field clubhouse.
The New York Daily News said Tuesday the alleged incident involved the theft of a bat and glove from Jeter's locker, which came to light when Rivera's teammates learned of the sale of the items.
After the players voted unanimously to kick Rivera off the team, Yankees General Manager Brian Cashman announced at a hastily called Monday night news conference that Rivera had been given his unconditional release, the report said.
"I will not go into details," Cashman told the newspaper. "He is no longer a member of this organization."
Rivera, 28, refused to speak to the media, and Yankee players and management refused to disclose details of the incident.
"I won't be able to say anything about what happened," Yankees closer Mariano Rivera, who is Ruben's cousin, told Newsday. "If someone is to say something, it will be him."
Incidents of clubhouse theft occurred recently in basketball and football.
Last year, John Croce, the Philadelphia 76ers strength coach and brother of former team president Pat Croce, was fired when hidden cameras caught him stealing money out of Allen Iverson's locker.
New Orleans Saints receiver Albert Connell was arrested for stealing money from teammate Deuce McAllister this past season.
Ruben Rivera once was considered a top prospect in the Yankees' organization but frustrated management with his lack of discipline on and off the field and was traded to San Diego as part of the deal which brought pitcher Hideki Irabu to New York in 1997.
Rivera spent four disappointing seasons with the Padres and played last year with the Cincinnati Reds before signing with the Yankees in the offseason.
Rivera and Jeter have known each other since 1992, when they played together for Tampa of the Rookie League.