The defect was discovered after the French international passed a medical on Thursday and put pen to paper on a five-year contract to complete his transfer from top-flight rivals Nice.
Nothing showed up at his medical but the problem emerged later when doctors took a closer look at scans.
"More tests will be performed on Monday to give clear answers to Loic," Marseille doctor Christophe Baudot told reporters on Friday. "He will not play for as long as there are any doubts."
"The news we've had since (Thursday's scans) is reassuring but we have taken this decision because the most important thing for us is not to take risks with our players' health," said president Jean-Claude Dassier.
Last year, forward Steve Savidan's move from Caen to Monaco collapsed for the same reason and he, too, had to hang up his boots.
"It's a nuisance but the most important thing is my health," said Remy who joined Marseille for an undisclosed fee.
"It's a pity that tests did not show that earlier. I'm a bit worried but not to the point I fear I might have to end my career."
