Rookie Brandon Maurer gets the ball for a spot start Wednesday night against Houston at Safeco Field.Hernandez already missed his scheduled start Sunday against Tampa Bay due to back stiffness after leaving his most recent outing Sept. 2 due to lower back cramps. Now he'll be scratched again with no set timetable for his return."I guess you'd call it a minor oblique strain on the left side, if you had to put a label on it, but it was more just stiffness," manager Eric Wedge said.Maurer (4-7, 6.85 ERA) started the year in the rotation for the Mariners (65-80) but was sent to Triple-A Tacoma after going 2-7 with a 6.93 ERA in 10 starts in the season's first two months. Perhaps the worst came in a 16-9 shelling versus Houston on April 9 as the right-hander gave up six runs and seven hits in only two-thirds of an inning.Maurer has been used as a long reliever since being recalled in late July, posting a 6.64 ERA over eight appearances spanning 20 1/3 innings. He hasn't thrown since a 1 1-3-inning appearance in a 7-6 loss at Kansas City on Thursday."I'm excited. I'm ready to give it another go. I just didn't know when," Maurer told the team's official website. "I think I can go 100 (pitches). I feel good, so I will go until they tell me I can't go anymore. I feel about as fresh as I can right now."The Astros (49-96) had another solid night at the plate, collecting 17 hits in a 13-2 victory over Seattle on Tuesday despite missing All-Star Jason Castro for a third straight game due to a sore right knee. Matt Dominguez, Chris Carter and Jose Altuve were a combined 9 for 15 with five doubles and six RBIs. Altuve's 21 hits this month lead baseball.Houston is averaging 5.3 runs over its last nine games while batting .280, including a .333 clip with runners in scoring position."It definitely is contagious," manager Bo Porter said after his club recorded a season-high 10 extra-base hits. "You start to swing the bat and you start to see your teammates getting hits."Starter Brad Peacock (4-5, 5.62) could likely use another big night from the offense given his results against the Mariners this year. The right-hander is 1-2 with a 9.64 ERA.Kyle Seager, Dustin Ackley and Justin Smoak are a combined 9 for 20 off him.The Mariners dealt shortstop Brendan Ryan to the New York Yankees on Tuesday night in exchange for a player to be named later. The emergence of rookie shortstop Brad Miller, who is hitting .259 with 35 runs in 66 games, made Ryan more expendable as he was hitting a career-low .192.