"You try and compartmentalize a little bit and kind of break things down, game by game, pitch by pitch," Fister said. "Obviously, it's a frustrating thing to not get your job done and not help the team put up the victory."
Astros manager A.J. Hinch, who's had to patch the rotation together following the likely season-ending injuries to Keuchel (shoulder inflammation) and McCullers (mild elbow sprain), said Fister simply had a hard time ending at-bats in his favor Sunday.
Kyle Seager's two-run double in the first put the Mariners ahead, 2-0, and Seth Smith tagged him for homers in the third and fourth.
"They were clearly trying to lay off some secondary pitches that were close, drew a couple of walks, came up with the big blow when they needed it," Hinch said. "Good team offense for them today, which was at Fister's expense."
Fister was the Astros' most consistent starting pitcher in the first half of the season, going 8-3 with a 3.21 ERA in his first 14 starts, 11 of which were quality. In 87 innings in that span, he allowed just 76 hits. In his last 16 starts, covering 87 innings, Fister is 4-9 with a 5.69 ERA and 109 hits allowed.
Considering the Astros are already short-handed in the rotation with two weeks to go in the season, there's not much Hinch can do but keep giving the ball to Fister. If he can iron things out, Fister probably gives the Astros a better shot to win than unproven rookies Brady Rodgers and David Paulino.
"He's always going to battle," Hinch said. "I don't worry about him showing up for work and giving his best. He's a consummate pro. He expects a lot out of himself, so when he wobbles a little bit he takes it pretty hard and wants to try to find a solution."
Brian McTaggart has covered the Astros since 2004, and for MLB.com since 2009. Follow @brianmctaggart on Twitter and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.