The Orioles open a three-game series on Monday night looking for their ninth straight win against the Mariners and sixth in a row at Safeco Field.
Baltimore (15-10) will try to bounce back after failing to close out its first four-game sweep in Oakland since 1987 on Sunday. The Athletics tied it with two in the ninth and scored the winning run on Manny Machado's throwing error in the 10th inning for a 9-8 victory.
Nate McLouth and Machado each had four hits and Chris Davis hit his league-leading ninth home run as the Orioles continued their offensive tear. They hit .315 with 11 doubles, five homers and scored 28 runs while winning three of four in Oakland to start a season-high 11-game road trip.
Zach Britton makes his season debut for Baltimore after going 1-0 with a 1.98 ERA in three starts at Triple-A Norfolk. The left-hander allowed one run over six innings in his last start for the Tides on Thursday.
Britton, who went 5-3 with a 5.16 ERA in 11 starts last season, has no record and a 2.57 ERA in two career starts against the Mariners, walking two and striking out 11.
He allowed three hits over nine shutout innings in a 2-1, 12-inning win over Seattle on May 12, 2011.
Baltimore pitchers have posted a 1.84 ERA during the team's eight-game winning streak in this series.
This time, the Mariners (11-16) are looking to build off their first series victory after taking three of four from the Los Angeles Angels with a 2-1 home win on Sunday.
"We wanted to win this series bad," Morse told the team's official website. "We're going to have a lot of these one-run games, and to come out on top like that means a lot for the character of this team."
Former Oriole Joe Saunders (1-3, 6.33 ERA) takes the mound after allowing eight runs and 11 hits - including a pair of homers - over five-plus innings in a 10-3 loss at Houston on Wednesday.
"Just a bad day. That is all I care to say,'' said Saunders, who has given up 15 runs and 20 hits in his last two starts. "We'll just turn the page on it, go get them next time and forget about this one.''
Saunders surrendered two runs over 11 1-3 innings in two starts for Baltimore in the 2012 playoffs and has won all five of his despite a 4.73 ERA in seven career starts against the Orioles.
Baltimore, though, has 11 home runs and 16 doubles against left-handers, ranking near the top of the majors in each category.
Matt Wieters has a homer, single and a walk in three career plate appearances against Saunders, though Davis is 2 for 13 with a homer and six strikeouts in this matchup.
Machado is hitting .433 over his seven-game hitting streak, while former Mariner Adam Jones is batting .342 during his nine-game tear.
Seattle's Dustin Ackley has batted .406 in a nine-game hit streak, but he's batting .205 in 39 career at-bats against the Orioles.
The Mariners rank near the bottom of the majors with a .212 batting average against left-handers.