Rooney played on the varsity tennis team during his junior and senior years, posting a 4-2 record, before graduating as a philosophy major in 1924. He also served as manager of the team in his last year.
 
In 1949 he began coaching boy's tennis at Fordham prep. Rooney's greatest claim to fame was during his time as women's tennis team coach in 1972. He coached them to an unbelievable 280-34-2 record including five MAAC championships and the 1990 Patriot League title. Included in the team's undefeated dream season (11-0) was the continuation of a winning streak that dates back to the 1989 season and now ranks as one of the longest in school history at 26 straight.