The Nationals have now set two-thirds of their starting rotation for the three-game series against the Los Angeles Dodgers that begins Monday at Nats Park.
Washington right-hander Jordan Zimmermann will battle 5-0 Dodgers righty Zack Greinke on Monday. And following Sunday's loss in Philadelphia, Nats manager Matt Williams announced that right-hander Stephen Strasburg would start for the home team on Wednesday against ex-Nat Dan Haren.
That leaves only Tuesday's starter for the Nationals undecided, and Williams said a decision wouldn't be made on that assignment until after Monday's game.
If he's not used in relief Monday, left-hander Ross Detwiler could get the nod. If Detwiler is needed Monday, the Nats could turn to rookie righty Blake Treinen, who could be recalled from Triple-A Syracuse.
Regardless of who pitches for the Nats, they will have a daunting opponent: lefty Clayton Kershaw, the reigning National League Cy Young Award winner who will come off the disabled list to make his first start since March 22 in Australia after being sidelined with a strained back muscle.
Right-hander Doug Fister, currently on the 15-day disabled list with a strained lat, was in consideration to make Wednesday's start for Washington, but Williams said Fister would instead open the three-game interleague series at Oakland on Friday. That will be Fister's regular season debut for the Nats after being acquired in the offseason from Detroit.
Fister is 5-5 with a 3.17 ERA in 12 career starts against the A's, and 2-3 with a 2.41 ERA in six starts at O.co Coliseum. In 12 interleague games, including 11 starts, Fister is 4-3 with a 2.09 ERA.
Also, Williams said the Nats would re-evaluate injured outfielder Scott Hairston (left oblique strain) after Sunday's minor league rehabilitation game with Syracuse before making a decision on whether he'd be activated for Monday's game.
Hairston played nine innings in left field Sunday, going 0-for-4 and is now hitting .100 in three games with the Chiefs.