Cardinals right-handed pitcher Lance Lynn returned to St. Louis on Tuesday for tests and will have an MRI after experiencing forearm tightness during Sunday's start.
Cardinals officials told the St. Louis Post-Dispatch that they wouldn't address Lynn's condition until Friday and wouldn't say whether the pitcher would make his next start on Saturday.
Lynn, who is 4-4 with a 3.07 ERA this season, left Sunday's game against the Dodgers after throwing 98 pitches.
The Associated Press contributed to this report.