In May 1986, Oliveras took over as skipper of the independent Miami Marlins after Fred Hatfield was fired. He had been "widely praised for his work in the Puerto Rican Winter League", according to Baseball America's 1987 Statistics Report, and the Marlins won the most games they had in eight years.
The next year, Oliveras was hired by the California Angels organization and hmanaged the Midland Angels from 1987 to 1989. He moved up to Triple-A, managing the Edmonton Trappers from 1990 to 1992 and the Vancouver Canadians in 1993. After that, he became a coach for the Angels in 1994 and was a member of the Chicago Cubs staff from 1995 to 1997.
In 1998, he managed the Kinston Indians. He took over as skipper of the Orlando Rays in 2002, then moved down to the Charleston RiverDogs in 2003, and then back up to the Bakersfield Blaze in 2004. In 2005 and 2006, he was a coach for the Montgomery Biscuits under manager Charlie Montoyo.
In between, Oliveras played for the Petroleros de Poza Rica of the Mexican League and piloted the Cangrejeros de Santurce club to Caribbean Series championships in the 1993 and 2000 tournaments.
- Baseball Reference – Minor Leagues career
- "Cubs All-Time Coaches". Baseball-Reference.com. Retrieved 2009-10-02.
- "Manager Mako Oliveras Leads All New B-Mets Coaching Staff". bmets.com. 2007-02-01. Retrieved 2009-02-04.
- Rubin, Adam (2007-02-01). "Jeff Francoeur homers, Pat Misch goes distance as Mets top Marlins". nydailynews.com. New York. Retrieved 2009-09-29.
- Baseball Reference Bullpen – 1993 Caribbean Series
- Baseball Reference Bullpen – 2000 Caribbean Series
- Espn.com – Mako Oliveras iguala récord (Spanish)