Rodriguez (shoulder) threw a scoreless inning for Triple-A Memphis on Sunday during a rehab appearance, John Denton of MLB.com reports.
Rodriguez threw eight pitches in the contest with six landing for strikes. The right-hander was the Cardinals' Rule 5 draft pick in December, and his rehab stint from right shoulder inflammation will expire on May 9. After that, Rodriguez will either need to be promoted to the major-league roster or the Cardinals will have to offer him back to the Yankees.