Williams will go up against Romanian Irina-Camelia Begu in the third fixture of the afternoon at the center court. Following a defeat in the fourth round at the Miami Masters, the top seed has played well so far here. She got her revenge as she ousted Russian Svetlana Kuznetsova in the quarterfinals yesterday following wins over Anna-Lena Friedsam and Christina McHale in the second and third rounds here.
The Romanian has had an excellent tournament so far as well and she is yet to drop a set. She defeated Misaki Doi via a second set tie-breaker in the quarterfinal after having downed Margarita Gasparyan, Victoria Azarenka, and Daria Kasatkina in the first three rounds here. This will be the first career meeting between these two opponents but Serena starts as the favourite.
Top seeded Djokovic will take on sixth seeded Kei Nishikori of Japan up next. Djokovic ousted Rafael Nadal in straight sets in yesterday’s quarterfinal after having beaten Stephane Robert and Thomaz Bellucci in the second and third rounds here.
Nishikori was up against Dominic Thiem of Austria in the quarterfinal and did well to defeat him in straight sets. Prior to that, the Japanese had overcome challenges from Viktor Troicki and Richard Gasquet. Djokovic has won eight of the 10 previous head-to-heads between these two men and should start as the favourite to make the final on Sunday.
Third seeded Spaniard Garbine Muguruza will get us under way at noon as she takes on Madison Keys of America at the center court. Muguruza has been on song here in Rome with wins over Ekateria Makarova, Julia Estapenko and Timea Bacsinszky in the last three rounds. She is yet to drop a set at the tournament.
Keys needed three sets to down Barbora Strycova in the quarterfinals after having defeated Andrea Petkovic, Petra Kvitova and Timea Babos in the first three rounds. Keys had the last laugh in the only previous head-to-head between these two ladies but things could turn out differently this time around.
Second seeded Andy Murray of Great Britain will play French qualifier Lucas Pouille. Pouille had a walk-over from Juan Monaco in the quarterfinals after having beaten Ernests Gulbis and David Ferrer in the second and third rounds of the main draw. He did not feature in the first round following failure to defeat Mikhail Kukushkin in the final qualifier.
Murray has been quite solid in this tournament this year. He started with a second round win over Kukushkin and followed it up with wins over Jeremy Chardy and David Goffin in the next two rounds to set up this semi-final clash.
Although there have been no previous matches between these two, Murray will start as the favourite on Saturday on the backs of a great campaign here.
Here's the 2016 Rome Masters of Play for Saturday, May 14:
Starting at: 12:00 pm
Garbine Muguruza (ESP)  v Madison Keys (USA)
[LL] Lucas Pouille (FRA) v Andy Murray (GBR) 
Serena Williams (USA)  v Irina-Camelia Begu (ROU)
Novak Djokovic (SRB)  v Kei Nishikori (JPN) 
[PR] Julien Benneteau (FRA)/Edouard Roger-Vasselin (FRA) v Bob Bryan (USA)/Mike Bryan (USA) 
Starting at: 12:00 pm
Andrea Hlavackova (CZE)/Lucie Hradecka (CZE)  v Ekaterina Makarova (RUS)/Elena Vesnina (RUS) 
Vasek Pospisil (CAN)/Jack Sock (USA)  v Rohan Bopanna (IND)/Florin Mergea (ROU) 
Sania Mirza (IND)/Martina Hingis (SUI)  v Irina-Camelia Begu (ROU)/Monica Niculescu (ROU)