Left fielder Ben Gamel made his 2018 debut Wednesday night in a 7-1 loss to the Houston Astros, going 0-for-2 with a walk.
Gamel had been sidelined since early March with a strained right oblique. With no spring training to speak of, he played 10 minor-league rehabilitation games before being activated.
"I feel good, 100 percent," Gamel told MLB.com. "I'm ready to roll."
Gamel batted .275 as a rookie last season for the Mariners, with 11 home runs and 59 RBIs.
"Ben is going to play," Mariners manager Scott Servais told reporters before Wednesday's game. "He had a nice season for us last year. We'll take it day to day, matchup-wise, where it goes from there. We're carrying five outfielders. It's a little different, but that's what we're going with and we'll let you know when it changes."
That was in reference to 44-year-old Ichiro Suzuki, who signed with the Mariners, the team he started his major-league career with, when Gamel was injured. There was speculation in the media that Suzuki, batting .212, would be the one to go when Gamel returned. Instead, left-hander Ariel Miranda was sent down to Triple-A Tacoma.
Gamel, who bats left-handed, likely will platoon with the right-handed-hitting Guillermo Heredia.
"(Heredia's) done a nice job for us and we certainly know he's a plus-plus defender," Servais said. "What he does defensively is awesome. We still have to keep him going with a spot start here or there against a righty, but primarily it's going to be against left-handed pitching. Ben and Ichiro will get the bulk of the time against the righties."
With catcher Mike Zunino (strained left oblique) and right-hander Erasmo Ramirez (strained right lat), the fifth starter, expected back by the end of the weekend, that would leave only first baseman Ryon Healy (sprained right ankle) still on the disabled list. If all goes well, Healy, who worked out with the team Wednesday afternoon, will start a minor-league rehab assignment this weekend.
Despite avoiding Astros ace Justin Verlander in this series, the Mariners have scored only four runs through the first three games.
They beat Dallas Keuchel 2-1 in the opener, then scored one run in each of the next two games, off Lance McCullers Jr. and Gerrit Cole. One run came on a homer by Robinson Cano and the other was unearned.
The task gets no easier Thursday as they'll face right-hander Charlie Morton. The 34-year-old is 2-0 with a 1.00 ERA in three starts this season. In his last start, Morton did not get a decision after yielding two runs on four hits while striking out 12 in six innings against the Rangers.
In four career starts against Seattle, Morton is 1-2 with a 3.80 ERA.
"They have good pitching and we know that," Servais said. "We have to have more competitive at-bats. ... We had been swinging the bats so well and we got shut down on Sunday (by Oakland's Sean Manaea) and here the past couple of days, as well. We got to get it going offensively again and our guys know that."
The Mariners will send left-hander Marco Gonzales (1-1, 8.25 ERA) to the mound. He lasted only 3 1/3 innings in his most recent start, giving up five hits and four runs against Oakland in a game the Mariners eventually won 10-8.
Gonzales has pitched only once against the Astros, a scoreless inning of relief last September.