Signed in 1955 as an amateur free agent, Davis made his major-league debut with the Kansas City Athletics on July 26, 1958, pitching the first six innings of  a 4-3 loss to the Baltimore Orioles. He won 16 games at Shreveport in 1959. The Washington Senators selected Davis from Kansas City following the 1960 season in American League expansion draft, then traded him the same day to the Los Angeles Angels for Jim Mahoney. But rather than report to the Angels, Davis retired and returned to Yale to continue his education. He had a Jewish father.