The White Sox placed Slater on the 10-day injured list Saturday with a torn meniscus in his right knee.
It was unclear why Slater was scratched from the lineup ahead of Friday's game, but those questions have now been answered. The White Sox haven't established a return timeline for the 32-year-old just yet, but he'll likely be sidelined for a few months. Greg Jones was recalled from Triple-A Charlotte in a corresponding move.