Long time ago I read about this strong GM who was one of Kasparov's analysts in the 90s. The thing is that if I search by "Yuri Dojoian" I only get a few results, only in Spanish media, like this one. I'm almost sure there is another way to write his name, but I have no idea how could it be.
I think the player you are referring to is Yury Dokhoian. According to his FIDE profile and Olimpbase profile he has not played competitive chess since 1994. According to his Wikipedia page he was Kasparov's second for many years and later started working with Karjakin. Chessgames.com has 173 of his games.