HOUSTON -- If misery truly loves company, the Astros and Mariners should be able to cozy up over a few cups of coffee this week in Seattle and tell some sad tales.

The fact the Astros are still clinging to a playoff spot in the American League after their worst stretch of baseball in recent memory -- capped by a 6-5 loss Sunday afternoon against the Royals, who swept a three-game series at Minute Maid Park -- is an indictment of the Mariners, who were swept by the Rangers in Arlington.

Thus, the Rangers have taken control of the AL West entering the final week of the season, and the Astros and Mariners will meet Monday to start a crucial three-game series with massive playoff implications. Houston currently holds the final Wild Card slot in the AL, one-half game ahead of Seattle.

• Games remaining (6): at SEA (3), at AZ (3)
• Standings update: The Astros (85-71) are in second place in the American League West, 2 1/2 games behind the Rangers (87-68). Seattle (84-71) is a half-game behind Houston for the third and final AL Wild Card spot. The Astros hold the season tiebreaker against the Rangers, but not the Mariners.

“The champions always have pressure, and I think the guys know what they need to do to get out of this,” Astros first baseman José Abreu said. “It starts tomorrow.”

The Astros couldn’t overcome four home runs allowed in three innings by rookie starting pitcher Hunter Brown and watched the Royals hold on for a stunning sweep. Houston went 1-5 in its final home games of the season, with the only win coming in a 2-1 walk-off victory over the Orioles on Wednesday. The Astros have lost nine of their last 12 games, including two defeats against Oakland and five against Kansas City.

“This is the big leagues, and every team is good enough to win,” center fielder Mauricio Dubón said. “They’re not good in the win column, but that’s baseball and it sucks not to get the win right now and getting swept. We’ve got to forget and go to Seattle and play.

“Everybody knows what’s going on -- just go in there and be focused and try to win three baseball games.”

Both the Astros and Mariners lined up their top three starting pitchers for the series, beginning with Justin Verlander for Houston and Luis Castillo for Seattle on Monday. The Mariners have already won the season series over the Astros -- the No. 1 tiebreaker -- so Houston would have to finish one game ahead of Seattle.

“We’ve been good on the road [46-29] and it’s going to be an interesting series, but we’ve got the guys here,” Dubón said. “It’s just a matter of coming and putting good at-bats and throwing the ball well. Sometimes baseball happens.”

Brown breezed through an 11-pitch first inning before giving up homers to Nelson Velázquez and Matt Duffy in the second inning. Salvador Perez and Velázquez tagged him for back-to-back home runs in the third to put the Royals ahead, 6-2. Houston managed only three hits after the second inning, including a leadoff homer by Yordan Alvarez in the fifth that made it 6-5.

“I couldn’t get the fastball away to the right-handed hitters,” said Brown, who has a 6.81 ERA and 1.63 WHIP in his last 17 starts. "The ones that stayed middle or went inside, they were able to hit it out of the park.”

Brown lasted only three innings, allowing six runs, and saw his ERA rise to 5.12 in 154 2/3 innings. José Urquidy restored order by throwing three scoreless innings, but the Astros’ offense couldn’t come up with a clutch hit once again. Houston was 1-for-10 with runners in scoring position (4-for-30 in the series).

“We had trouble scoring with runners in scoring position,” Astros manager Dusty Baker said. “That makes it tough, but it’s tough when you’re always playing comeback, too. Those twin three-run innings really hurt us. Our bullpen shut them down, and their bullpen shut us down. Boy, it’s tough to take. What can I say?”

When asked how the Astros are going to respond in Seattle, Dubón said emphatically: “We’re Houston.”

“Everybody in the clubhouse is a dog,” he said. “It’s a matter of going in there and taking care of business.”