Richards was making his first Major League start since May 1, 2016. The 28-year-old ace missed nearly all of last season after suffering a partially torn ulnar collateral ligament, though he opted for a stem-cell injection, rather than Tommy John surgery, to attempt to heal his damaged right elbow.
Manager Mike Scioscia said Thursday that the Angels will wait for Richards to be examined by team doctors before deciding whether he'll make his next start Tuesday against the Rangers.
"I think our medical staff is going to look into things," Scioscia said. "They're confident this isn't connected to his other situation last year, so we'll wait for guidance. Tomorrow, he'll be evaluated and probably have some tests done to see what's going on. But Garrett is comfortable when he talks about it, so hopefully this is just a little bump in the road."
Maria Guardado covers the Angels for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.