IMDB lists Roman Mitichyan as playing “Mikhail” in the seventh and eighth episode, something that is confirmed on his official website (along with a picture of him and Kiefer Sutherland on set):
Roman is also an actor/stuntman in the movie and television industry. You may have seen him in TV shows like, 24, Numbers, Desperate Housewives, The Shield, Dexter and many more. Some of the movies you may have seen him in include, The Kingdom with Jamie Fox, Felon with Val Kilmer and Shadows in Paradise with Armand Asante and many more movies to list here.
It’s currently unknown on whether he is playing the character Mikhail on-screen, or working as a stuntman. We have contacted Mitichyan who has confirmed it is an acting role.
Source: Roman Mitichyan official website