French Open organisers criticised for women’s semi-final scheduling after rain delays
The decision was made after Wednesday's play was washed out, causing a logjam in scheduling at Roland Garros.
The women's semi-finals, originally scheduled for Thursday, were shifted to Friday, with British No 1 Johanna Konta to play Czech Marketa Vondrousova on Court Simonne Mathieu, the newly-built third show court.
Australia's Ashleigh Barty and American Amanda Anisimova will meet on the second-ranked Court Suzanne Lenglen in the other semi-final.
The men's semi-finals, which see Rafael Nadal play Roger Federer and Novak Djokovic clash with Dominic Thiem, both remain on Court Philippe Chatrier, the centre court, as planned.
"There is no doubt that scheduling has been challenged by weather conditions and the WTA understands the scheduling issues presented at Roland Garros," Simon said in a statement.
"We are, however, extremely disappointed by the scheduling of both women's semi-finals on outside courts. This decision is unfair and inappropriate.
"The four women who have played so well and made it this far have earned the right to play on the biggest stage.
"We believe other solutions were possible which would have been to the benefit of fans as well as all players."
Tournament director Guy Forget said on Wednesday more inclement weather could force the men's and women's finals to be pushed back respectively to Sunday and Monday.
In the similarly disrupted 2012 tournament, Nadal beat Djokovic in the men's final on the third Monday of the championships.