Updated

Bottom feeders in the American League West collide Monday night at Safeco Field, where the Seattle Mariners will open a three-game series versus the Houston Astros.

The Mariners had won two in a row and three of four games until dropping a 4-1 decision Sunday to the Tampa Bay Rays. The Rays scored all of their runs in the eighth and ninth innings and Mariners reliever Yoervis Medina was dealt the loss for giving up three runs in the eighth.

Erasmo Ramirez had a 1-0 lead going and did not figure into the decision with six scoreless innings. He struck out five and walked four batters.

"I loved his aggressiveness early in the game and he was able to hang on to it and sustain it," Seattle manager Eric Wedge said of his starter.

Kendrys Morales hit a home run and Brad Miller added two hits in defeat.

Taijuan Walker will make his third career start Monday before the Mariners shut him down to preserve his innings. Walker won his Major League debut on Aug. 30, when he allowed an unearned run in five innings of a 7-1 win at Houston. He then took the hill in Wednesday's 6-4 win at Kansas City, but was reached for four runs in five innings for a no-decision.

Walker, a right-hander, will make his first appearance at Safeco Field.

"Just treat it as any other start; I'm going to go out there and compete and give my team a chance to win," Walker told the club's website. "It's been great. The team's been very welcoming. Of course they haze you a little bit, but other than that it's been fun, had a good time.

"It would feel good to end the season on a good note. But if I don't, it is what it is, just go into the offseason and work hard and get ready for next year."

Houston opened a seven-game road trip by losing three of four against Oakland, including Sunday's 7-2 setback at the Coliseum. Jose Altuve and Brandon Barnes each had an RBI, while Lucas Harrell was drilled on the mound to the tune of seven runs and seven hits in only three innings.

Harrell was pressed into service after scheduled starter Paul Clemens was scratched with a blister.

"When you pitch out of the bullpen, the one good thing about that is you come to the ballpark every day believing that you're going to pitch," Astros manager Bo Porter said. "I don't think the short notice had anything to do with his performance."

The Astros have lost 10 of their last 13 games and hope Jarred Cosart can right the ship when he takes the mound Monday. The rookie right-hander is 1-1 in nine starts with a 2.13 ERA and hasn't recorded a win since July 12, going 0-1 in eight subsequent outings.

Cosart will face the Mariners for the first time Monday.

Seattle has won 10 of 16 matchups with Houston this season and had a six-game winning streak in this series stopped on Sept. 1 at Minute Maid Park.