Don't think he does at all. Gabriel is one of the best defenders in the league and has a hard enough time as it is without having to worry about covering 2 positions at the same with with Zinchenko running around all over the pitch away from his "actual" position.
Guy is super quick, strong as fuck, tall, great in the tackle and despite what some will have you believe, is very good on the ball. We're honestly lucky to have a player like that on our books. Far cry from the days of Koscielny, Squillaci, Mertesaker, Silvestre, Mustafi, Vermaelen etc.