On October 30, 1983, after completing his first professional season with the New York–Penn League's Elmira Pioneers, Mitchell and two fellow Red Sox farmhands, Anthony Latham and Scott Skripko,[1] were deep-sea fishing off the coast of Florida when their boat capsized.

[2] After two more seasons with the Red Sox organization, Mitchell was traded to the Mets along with Bob Ojeda, Tom McCarthy and Chris Bayer for Calvin Schiraldi, John Christensen, Wes Gardner and La Schelle Tarver on November 15, 1985.

Mitchell went 12–9 with a 3.39 earned run average in his first season with the Tidewater Tides, and received a call-up to the MLB that September.

Following the 1989 season, Mitchell and Joaquin Contreras were traded to the Baltimore Orioles for Cesar Mejia and Keith Hughes.

Mitchell signed with the Seattle Mariners organization in 1991, but appeared in just two games for the Calgary Cannons before suffering a season-ending injury.