On June 30, 2008, Gardner was called up and made his major league debut, batting leadoff and going 0-for-3 with a stolen base. On July 2, he earned both his first hit and first RBI, off fellow rookie Texas Rangers relief pitcher Warner Madrigal in the seventh inning. Gardner went on to steal second and eventually score in that inning. On July 26, 2008, Gardner was optioned back to AAA after the acquisition of Xavier Nady in order to continue to receive playing time. The Yankees again recalled Gardner on August 15.