Yost had hinted that the left-hander Vargas would "probably" start Game 4, but he made it official on Sunday. Vargas' start Tuesday night in Kansas City could come in a potential pennant-clinching game, as the Royals lead the series 2-0 after two wins on the road.
The 31-year-old Vargas hasn't pitched since Game 1 of the ALDS against the Los Angeles Angels on Oct. 2. He limited the Angels to two runs over six innings in what ended up being a 3-2 victory for the Royals in 11 innings.
Vargas was 11-10 with a 3.71 ERA and 1.27 WHIP in the regular season. He had 128 strikeouts and 41 walks in 187 innings.