He was drafted by the Oakland Athletics with the 26th overall pick of the 1979 Major League Baseball Draft. He was offered only $12,000 by Charlie Finley and opted to return to college when the commissioner's office refused to make him a free agent. Finley later offered the same amount of money with the stipulation of a September call-up, but Mike backed out when this was not put in writing. Stenhouse was selected fourth overall in the 1980 January draft by the Montreal Expos. He signed for a $32,000 bonus this time.
He was called up for the first time in 1982, striking out in his only at bat. After two sub-par seasons, he was traded by the Expos to the Minnesota Twins for Jack O'Connor. There he had career highs in games played (81), at bats (179), runs (23) hits (40), home runs (5), RBI (21), stolen bases (1), walks (29), and batting average (.223). That December he was traded by the Twins to the Boston Red Sox for Charlie Mitchell. In his final major league season he went 2 for 21 (.095), but walked 12 times and had an On base percentage of .424.
In 1996, Stenhouse was an announcer for the Expos on CIQC. He had previously been an analyst for the Pawtucket Red Sox.