WIMBLEDON, England—Garbine Muguruza, who has reached a Grand Slam semifinal for the first time at Wimbledon, says she admires Serena and Venus Williams, Maria Sharapova, and Martina Hingis.

"You see Williams sisters, the power, the aggressive, the confidence they have in themselves," the 21-year-old said. "You see Maria, she has a very good mentality and she's very focused during the whole match. Or Hingis, she's like very talented. You just take few things and make your perfect player."

Muguruza, who will play Agnieszka Radwanska in the semis, is 2-2 head-to-head against her opponent, with the Spaniard having beaten Radwanska two times this year on hard courts.

Serena Williams, who was shocked by Muguruza in the second round of the 2014 French Open, says the young Spaniard is already a formidable player.

"She's done well," said Serena, who beat Muguruza in the round of 16 at the Australian Open in three sets. "Like she didn't beat me then lose. She went on and had a tough three-set match against Maria [Sharapova]. I had a tough match with her in Australia. She's super young. I definitely see her as someone to watch and be careful for because she knows how to play. I think this is probably a good surface for her."

Muguruza added that she is looking forward to playing on Centre Court on Friday.

"Centre Court is special. It's the biggest court here in Wimbledon,” she said. "It's weird. It's like silence. There is no brands. It's different, but it's good."