SHANGHAI, China—Andy Murray will have an avid fan when he plays Roger Federer at the Masters Cup today.

Nikolay Davydenko faces the winner in the semifinals, and he’s dreading the prospect that it could be Federer—for good reason. He’s 0-12 against the second-ranked Swiss star, and 3-3 against Murray.

“Against Murray, I have more chance,” Davydenko said after beating Juan Martin del Potro 6-3, 6-2 Thursday to reach the semifinals.

Federer, who lost his opening match to France’s Gilles Simon, has to win to continue pursuit of his fifth Masters Cup title.