SEATTLE -- One day after getting a career-high four hits, Mariners first baseman Justin Smoak was sidelined Wednesday with tightness in his right hamstring.

Seattle manager Eric Wedge said Smoak's injury isn't serious, but "it's just not a smart move to push it right now."

Wedge said Smoak will be reevaluated on Thursday.

Second baseman Dustin Ackley got the call at first in Wednesday night's game against the Indians, his first start at that position in the Major Leagues. Ackley did play first base almost exclusively for three years at North Carolina, however.

"If there was any position I'd feel comfortable going back to, that would be the one," said Ackley, who converted to second base shortly after being drafted by the Mariners in 2009. "I made a couple starts in the outfield, but pretty much when I got to college I had so many arm problems I started at first and played there probably 95 percent of the time.

"It's almost my first home, but I haven't been there for a while."

Ackley said he'd have to borrow teammate Alex Liddi's first-base glove, just as he did when he played most of a Cactus League game at first toward the end of Spring Training.

Smoak said he started feeling his hamstring tighten up on Saturday, and it continued to bother him when he was running in recent days, including his four-single night in Tuesday's 9-8 loss to Cleveland.

"It's one of those things where I talked to Wedge about it and I'd rather miss a day than a couple weeks," Smoak said. "That's where we're at right now. It's day to day. Nothing serious. The goal is to get treatment, calm it down and be ready to go tomorrow."

Smoak said the leg doesn't bother him when he's swinging the bat, but only when he's running the bases, which happened four times Tuesday as he raised his average to .250.

"You get some hits and you want to stay in there," Smoak said, shaking his head. "You start feeling better at the plate, you don't want to come out. I tried my hardest to play today. It's just one of those things where it's early in the year and I don't want to miss a lot of time."

Injured Carp working toward return in Minors

SEATTLE -- Mike Carp has been working at designated hitter for almost a week in Triple-A Tacoma, but the left fielder needs to get his throwing arm fully recovered before being recalled by the Mariners, manager Eric Wedge said Wednesday.

Carp, 25, sprained his right shoulder in Seattle's Opening Day game in Tokyo on March 28 and has been on the 15-day disabled list, though he's eligible to return as soon as he's fully healthy.

Tacoma manager Darren Brown told reporters Carp will get his first outfield start on Thursday for the Rainiers. Wedge indicated it would be at least a few more days before he's brought back to Seattle.

"He's moving along," Wedge said. "We just need to get him in the outfield and have him start making that progress. He's swinging the bat well and feels pretty good. But we still need to get him in the outfield for a few [games]. We'll get through this week and see where we are."

Carp, who went 0-for-4 in Tacoma's 2-1 loss at Sacramento on Wednesday, is hitting .167 (4-for-24) with two RBIs through his first six games.

Center fielder Franklin Gutierrez is also on the 15-day DL, having been out since Feb. 28 with a partial tear of his right pectoral muscle. Gutierrez remains in Peoria, Ariz., working with Mariners Minor League players in extended Spring Training intrasquad games.

"Gut is still stretching it out, arm-wise," Wedge said. "He's hitting good and doing a good job down there, but we need to get him stretched out further before we can get him out on a rehab."

Iwakuma last player waiting to appear in game

SEATTLE -- Mariners reliever Hisashi Iwakuma is the only Major League player on an Opening Day roster who has yet to appear in a game.

The former Japanese starter was given a long-relief role after struggling much of the spring. Iwakuma, who signed a one-year contract with Seattle, was hit hard in an exhibition loss in Japan on March 26 before pitching well in out of the bullpen on April 2 when the Mariners returned to Arizona for more Cactus League games.

But Iwakuma has done nothing more than warm up in the bullpen several times in Seattle's first 12 regular-season games.

"It's just one of those things," manager Eric Wedge said prior to Wednesday's game with the Indians. "It happens from time to time through the course of a season. It just happens this time it's the beginning of the season.

"You keep hanging on to your long guy for that next day, and that's what we've been doing. That's the role he's in. We definitely want to try and get him in there. Multiple times we've tried to do it, and it just didn't work out. You have to work off the baseball game. That's simply what we're doing, working off the baseball game. It'll happen, we'll get him in there, we just haven't been able to do it yet."

White Sox starter Philip Humber had been the only other remaining unused player in the Majors, but he started Monday against the Orioles.

Moore to undergo surgery on meniscus

SEATTLE -- Mariners catcher Adam Moore received another setback Wednesday when it was learned he'd suffered a torn medial meniscus in his right knee while playing for Triple-A Tacoma and will undergo surgery Thursday.

Moore, 27, injured the knee Monday in Fresno, Calif., and was flown back to Seattle for tests. He was hitting .303 with a one home run and five RBIs for Tacoma after recovering from a broken bone in his wrist that cost him the final three weeks of Spring Training.

Moore opened 2011 on Seattle's 25-man roster, but he suffered a season-ending knee injury in his second game. That injury was also to the medial meniscus in his right knee, though it won't be known if this problem is as serious until surgery is performed by Mariners medical director Dr. Edward Khalfayan.

"Poor guy. I don't know what to say about it," Seattle manager Eric Wedge said. "I'm hoping it's more in that 4-6 week range this time so he can get back and play. He's been snake-bit, no doubt about it."

Moore, a sixth-round Draft pick in 2006, has played parts of the past three seasons with Seattle, batting .197 with five home runs in 68 games.

Worth noting

• When shortstop Brendan Ryan walked four times in Tuesday's 9-8 loss to the Indians, it was the most bases on balls by a Mariner since Ryan Langerhans took four walks on April 8, 2011, also against Cleveland.

The four walks raised Ryan's on-base percentage from .290 to .361.

• At the other end of the walk spectrum, Mariners starter Blake Beavan has issued just 16 free passes in his first 17 Major League starts (over 110 1/3 innings). The last Major League pitcher with fewer walks in his first 17 starts was Roy Oswalt, who walked 15 over 113 2/3 innings in 2001.

• The Mariners are offering free tickets for a home game in April or May, as well as a $5 credit at the concession stands to all fans who attended Opening Night last Friday at Safeco Field. There were long lines at the concession stands that night due to a failure of the computer system running the cash registers at the park.

Mariners president Chuck Armstrong called the experience "unacceptable" and offered his apologies to everyone who was inconvenienced. More information about the Opening Night ticket make-good offer is available at www.mariners.com/OpeningNight.