The 26th-ranked Safarova and the 11th-ranked Errani have met twice at WTA tournaments and are 1-1.
No.6-ranked Petra Kvitova will play the second singles for the host against the 54th-ranked Camila Giorgi.
The winner faces Australia or Germany in November's final.
The two have won the last five Fed Cups: The Czechs in 2011 and 2012, and Italy in 2009, 2010 and last year.
- Sports & Recreation
- Lucie Safarova
- Sara Errani
- Petra Kvitova
- Klara Koukalova