Gael Monfils has pulled out of France's Davis Cup quarter-final clash against the United States and will be replaced by Gilles Simon, the French tennis federation (FFT) said on Monday. The 25-year-old Monfils, who had been picked alongside Jo-Wilfried Tsonga, Michael Llodra and Julien Benneteau, for the tie on the Monte Carlo clay courts starting Friday, has a side strain. Monfils, ranked 14th in the world, pulled up during training on Sunday. Ultrasound and MRI (magnetic resonance imaging) scans revealed that he had torn his left internal oblique muscle, the federation added. The player has been told to rest for two weeks.