"I see (Stephens) as a dangerous player. ... And she has, of course, a lot of things in her game that brought her to become a Grand Slam winner," Mouratoglou said. "But whoever is dangerous, Serena is still Serena. My job is to make her the best she can. And when she's the best she can - she's not every day, all her life, but she is quite often - then you have to go get her."