Saint-Etienne striker Jean-Christophe Bahebeck was taken to hospital on Sunday with breathing problems after being taken off at half-time of the 2-1 Ligue 1 victory over Bastia.
He is set to undergo further tests after one of the club`s vice-presidents Bernard Caiazzo denied the 22-year-old had suffered a heart-attack.
"After suffering breathing problems during the match betweeen Saint-Etienne and Bastia, Jean-Christophe Bahebeck was hospitalised for further tests," the club said in a statement after the match.
"It was a drop in blood pressure, not a heart-attack," Caiazzo told AFP.
The match was played in searing heat in mid-afternoon with temperatures reaching 35 degrees Celsius on one of the hottest days of the year in France.
"I don`t have all the information. We will put confidence in our medical staff and of course show the player the utmost care," added Caiazzo.
Bahebeck is on loan at the club after joining from champions Paris Saint-Germain in the off-season.