South Africa paceman Wayne Parnell is undergoing tests on his heart after he was taken off the field during Kent's Royal London One-Day Cup defeat at Somerset on Tuesday.
Parnell could only bowl four overs during the match at Taunton and the left-armer will undergo further examinations on Thursday.
A Kent spokesman said: "Wayne left the field during Tuesday's match at Taunton as he was feeling unwell.
"He wanted to return to the field after examination by the club's medical staff but did not as a precaution.
"In consultation with doctors at Cricket South Africa, Wayne will receive further check-ups today."
Parnell is in the Proteas' squad for the ICC Champions Trophy in England next month.