Stan Wawrinka was scheduled to face Adrian Mannarino in the first round of his home-country tournament in Basel.
Unfortunately, the 33-year-old’s comeback season from two knee surgeries was cut short.
Wawrinka withdrew with a back injury, a day after practicing with countryman Roger Federer before a highly appreciative crowd.
He said he hurt his back during that practice, and had to stop after 20 minutes Monday. Wawrinka said it wasn’t serious, but that it was a better move to end the season now and focus on preparation for 2019.