"I can't make any excuses for what I did tonight," he said. "It's one of those nights I didn't do my job at all. I put our team in the hole from the get-go. That hurts me and the team. There is no excuse.
"The ball came up in the middle of the plate. [The Padres] are whacking at it, too. That's unacceptable."
After Fister left the game, right-hander Blake Treinen and left-hander Matt Grace pitched a combined six innings, allowed one run and struck out seven batters.
Treinen was clearly at his best on this day, striking out six in four innings, his longest stint of the year. He gave Washington a chance to get back into the game. Treinen's only blemish was allowing a solo homer to Cory Spangenberg in the fourth.
"My goal was to go out and get as many innings as I could for bullpen," Treinen said. "I kept us in the game and gave us a chance to make a run. Whatever happens, happens. I was trying to get quick outs to allow myself to go as deep as I can."
The job that Treinen and Grace did meant the Nationals have fresh arms for Friday's game against San Diego. With the exception of Treinen and Grace, the right-handers like Drew Storen and Aaron Barrett and left-handers such as Sammy Solis and Matt Thornton are ready to pitch if needed.