According to an announcement from the Nationals, Strasburg has been scratched with an "upper back strain" and Nats' right-hander Yusmeiro Petit will take his place tonight in the series opener in Dodger Stadium.
Strasburg, 27, is (10-0) through 14 starts this season with a 2.90 ERA, a 2.83 FIP, 24 walks (2.23 BB/9), 118 Ks (11.42 K/9) and a .218/.275/.346 line against in 93 IP, and he had a 13-start winning streak going heading into tonight's planned outing that stretches all the way back to last September.
Strasburg has been dominant on the mound since returning from the second of two DL stints last season, with the Nats 17-1 in his last 18 starts, and before tonight there was no word that he was dealing with any upper back issue.
The first of three with the Dodgers in LA was supposed to feature a showdown between Strasburg and Kershaw, but as the Nationals announced, it will now feature utility pitcher Yusmeiro Petit on the mound for the visiting Nationals.
Strasburg vs Kershaw would have been the first matchup in over 100 years featuring two starting pitchers with double-digit wins this early in a season.
The previous earliest date it happened, as the Nationals mentioned in their pregame notes, was a June 22, 1962 meeting between LA left-hander Sandy Koufax (10-2) and Cincinnati Reds' right-hander Bob Purkey (12-1).
RHP Stephen Strasburg has been scratched from tonight's start vs. LAD with an upper back strain. RHP Yusmeiro Petit will start.— #VoteNats (@Nationals) June 21, 2016
More info on the upper back strain when it's available, though it probably won't be until after tonight's game when Nats' skipper Dusty Baker talks to reporters.