SEATTLE -- The Mariners' lineup took another step closer to being at full strength on Sunday. Outfielder Mitch Haniger was activated from the 10-day disabled list and outfielder Boog Powell was optioned back to Triple-A Tacoma. Haniger hit second and played right field for the Mariners on Sunday. 
Haniger had a .342 average with four homers and 16 RBIs in 21 games before being sidelined with a strained right oblique muscle he sustained on April 25 at Detroit. Manager Scott Servais confirmed before Friday's game that Haniger would reclaim the starting right-field spot upon his return, although he won't play every day to prevent future flareups.
Haniger's return provides Servais an embarrassment of riches in the outfield, with Ben Gamel and Guillermo Heredia, who have both had stellar starts at the plate, and Jarrod Dyson, who plays outstanding defense, all complementing Haniger.
"They're all going to play a lot," Servais said. "I think we are in a really good situation. With what Gamel and Heredia have done, they earned [a chance] to continue to stay in that rotation. … Even Haniger isn't going to play every single day. I think we have to be smart with how much he's out there, knowing that the other guys can carry the load and we don't lose a whole lot.
"It's great. It's a great situation to be in."
The rookie outfielder spent the last five days on a rehab assignment at Triple-A Tacoma, playing three games in right field and two as designated hitter. A pinch-hitter spelled Haniger in his third at-bat in his final game Saturday. 
His time in Tacoma allowed him a chance to regain his swing and timing, but getting his legs back under him was the biggest step forward for Haniger.
"Swing has felt really good, timing has felt good," Haniger said. "That was the biggest concern, just getting my legs back in shape, because I hadn't been able to sprint for so long."
Powell was hitting .179/.324/.179 in 35 plate appearances this season.
There's no way of knowing if Haniger will pick up where he left off, but Servais said the team is "cautiously optimistic."
"He was playing at such a high level, he did get hurt, it's hard to imagine he'll come back at that level," Servais said. "We'll all take it, but I can be realistic, and he hasn't played a big league game in six weeks."
Haniger just knows he's excited to be back in the lineup.
"Every time you get hurt, it's frustrating, being on the DL is never fun," Haniger said. "I was just trying to do my best to be a good teammate, picking up guys in the clubhouse and keep the mood and the energy up throughout the game.
"I'm excited to be back up here with the team and contribute to the lineup and get some wins with the team that's playing really well."
Iwakuma scheduled for rehab start
Hisashi Iwakuma threw a two-inning simulated game Sunday and it went well enough for the Mariners to schedule him for a three-inning rehabilitation start -- about 45 or 50 pitches -- on Wednesday at Class A Advanced Modesto.
Servais said it will be the first of two rehab starts for Iwakuma.