We've seen an ambidextrous pitcher before in Major League Baseball. That would be Pat Venditte, who spent parts of five years with the A's, Rays, Mariners, Dodgers, Giants and Marlins.
The Marlins have reinstated pitchers Pat Venditte, Mike Morin and Josh A. Smith from the 60-day injured list and outrighted the trio to Triple-A, leaving the club with a 40-man roster.