Hudson is undergoing more tests on his forearm Friday, Derrick Goold of the St. Louis Post-Dispatch reports.
Hudson left Thursday's game against the Pirates due to an issue that was originally referred to as right elbow tightness. While an X-ray came back negative, the Cardinals are worried about a potential flexor tendon issue or some other forearm injury. Whether or not he can pitch again this season should become clear following the tests.