The Chinese fifth seed has been under the tutelage of the Argentinean, who at one time trained seven-time Grand Slam winner Justine Henin, since July 2012 and has helped her to the final four at Flushing Meadows.
Li was previously coached by her husband Jiang Shan, but she revealed that things didn't always work out too well between the pair.
"At least if he says something I will listen," Li said in a press conference.
"But if my husband is my coach, when he says something, I never listen. I just say, 'Okay, pass. Next one'."
Li faces world number one Serena Williams for a spot in the final on Friday.