Maria Paseka, a two-time world vault champion and four-time Olympic medalist, is out for the rest of the year after December back surgery, according to Russian news agency TASS.
Paseka, 22, earned the lone Russian title at worlds in October, repeating as champion on vault by edging American Jade Carey by .084. She handed Simone Biles her only defeat in a 2015 Worlds final, also on vault.
Paseka also took vault silver and bronze medals at the last two Olympics, as well as helping Russia to team silvers in London and Rio.