Mercedes will serve as San Francisco's designated hitter and No. 4 batter in Thursday's game against the Dodgers.
Despite going 1-for-11 in the first three games of the series, Mercedes will get another look as the Giants' DH in the finale. It's worth noting that the Giants faced four lefty starters in the series, so the righty-hitting Mercedes should still be viewed as a short-side platoon player.