(Jeff Roberson / AP)

Jordan Zimmermann would start Game 1 of the National League Championship Series on Sunday in Washington against the San Francisco Giants should the Nationals advance, Manager Davey Johnson said.

Zimmermann, 26, threw 12 pitches in relief on Thursday, three days after starting on Monday. He thew 63 pitches over three innings in a 12-4 loss to the St. Louis Cardinals in Game 2 of the National League Division Series.

Zimmermann has a career 3.19 ERA in 36 2/3 innings over six starts against the Giants. He started twice against them this season, winning only once. His first outing was one of his typical performances: one earned run on seven hits with seven strikeouts over six innings in a 9-3 win on July 3. In his second start against the Giants in a 6-1 loss on Aug. 14, he allowed two runs on eight hits over 5 2/3 innings.

Zimmermann was electric in his first career major league relief appearance on Thursday. His jet-fueled fastball zipped at 97 mph, more than normal, and his sharp slider topped out at 91 mph. He struck out the side in the seventh inning on 12 pitches. But, as Zimmermann admitted afterward, relieving is completely different than starting.

Edwin Jackson is slated to start Game 2 of the NLCS on Monday in Washington. Johnson didn’t address who would start Game 3 on Wednesday in San Francisco but it would be Ross Detwiler‘s turn in the playoff rotation should Johnson decide to stick with the same starters.