Wainwright returned to St. Louis on Wednesday for tests. The right-hander became the NL's first nine-game winner on Tuesday night by pitching seven innings in a 1-0 win at Tampa Bay.
Before Wednesday night's game against the Rays, Cardinals manager Mike Matheny said that everything the team had heard so far about Wainwright's elbow ''has been positive.''
Wainwright had elbow ligament replacement surgery in February 2011.
Matheny said the discomfort was on the other side of the elbow. He said the ligament was fine, aside from some inflammation.
Wainwright has had some elbow discomfort in recent starts, which the team has been monitoring. He is 9-3 with a 2.15 ERA in 14 starts for the NL champions.