SEATTLE -- Left fielder Ben Gamel, who had been sidelined for six weeks with a strained right oblique muscle, was activated off the 10-day disabled list on Wednesday as the Mariners continued regaining missing offensive pieces.
Left-hander Ariel Miranda, who pitched five innings of one-run ball in a spot start in Tuesday's 4-1 loss to the Astros, was optioned to Triple-A Tacoma to make room on the 25-man roster.
Catcher Mike Zunino is also expected to return from a strained oblique on Friday, when the Mariners open a 10-game road trip against the Rangers in Texas. Zunino was set to play his third rehab game for Class A Advanced Modesto on Wednesday, while first baseman Ryon Healy could head out on a rehab assignment this weekend as he works back from a sprained right ankle.
The Mariners already added designated hitter Nelson Cruz, who came off the disabled list Saturday, while right-handed pitcher Erasmo Ramirez is expected to rejoin the rotation Sunday in Texas to take the fifth-starter spot that Miranda filled Tuesday.
Gamel has played in 10 Minor League rehab games, five with Modesto and the last five with Tacoma. He went 1-for-3 with a run scored in Tuesday's 8-2 victory over Albuquerque and has hit .278 with a double and four walks in five games for the Rainiers after batting .294 with one double and four walks for Modesto.
"I feel good, 100 percent," Gamel said. "I'm ready to roll."
The 25-year-old played 134 games for Seattle as a rookie last season, posting a .275/.322/.413 line with 11 home runs and 59 RBIs.
Gamel's return gives the Mariners five outfielders, for now. The club signed Ichiro Suzuki to help in left field after Gamel injured his oblique on March 2, but Gamel is expected to get the bulk of playing time there.
"Ben is going to play," Mariners manager Scott Servais said. "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."
Guillermo Heredia will continue playing against left-handed pitchers.
"He'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."
Sending Miranda down gives the club a few days to decide whether to go with eight relievers or five outfielders, but another roster move will be needed when Ramirez is recalled.
Another decision will loom whenever Healy returns, as that will mean either sending down rookie first baseman Daniel Vogelbach or opting again to go with one fewer outfielder or reliever.
The initial plan was to carry just one first baseman, with utility man Andrew Romine capable of backing up there, as needed, but Vogelbach had a huge spring and has hit a pair of home runs while batting .242 filling in at first base and designated hitter in the early going this season.
Healy took part in Wednesday's pregame work again with the rest of the club and tested the ankle with some running drills. Servais said he'll likely head to either Tacoma or Double-A Arkansas this weekend.