A former world singles number one, Hingis plays exclusively doubles on the WTA circuit these days - she is currently ranked number one alongside her partner Sania Mirza - but had been touted for a singles comeback when Swiss number one Belinda Bencic was forced out of the last-four tie in Lucerne due to a back injury.
However, the Swiss, who have opted not to replace Bencic and will instead play with a team of three, have chosen Timea Bacsinszky and youngster Viktorija Golubic for Saturday's singles.
Bacsinszky will face Barbora Strycova in the opening rubber before Golubic, playing Fed Cup singles for the first time, takes on Karolina Pliskova.
The holders have also been forced to field a weakened team with Petra Kvitova and Lucie Safarova both absent so Pliskova is leading their bid to reach a fifth final in six years.
Hingis has been nominated for Sunday's potentially-decisive doubles rubber which follows the two reverse singles.
The other semi-final sees France host the Netherlands in Trelaze.