Last year, injuries forced the Twins to field late-season lineups that included Brian Dinkelman, Rene Tosoni, Rene Rivera, Luke Hughes and Joe Benson, so no wonder they had trouble scoring.

Now, there's no excuse. Joe Mauer and Justin Morneau are healthy, Josh Willingham is having a career season, injuries haven't really been a problem ... and after a nice midsummer surge, the Twins offense has gone missing again.

Seattle pitchers continued their mastery over the Twins on Tuesday night, as Hisashi Iwakuma held them to one hit over six innings in a 5-2 victory in front of a quiet 29,854 at Target Field, their smallest crowd in the ballpark's three seasons.

"Not many hits, not many great at-bats, really," Twins manager Ron Gardenhire said. "I don't know what to say; we're just kind of floating around offensively. We've got guys that can hit but we're not putting anything together, and it's kind of frustrating for everyone involved."

Twins starter Scott Diamond (10-6) gave up a two-run double to Kyle Seager in the third inning and a three-run homer to Dustin Ackley in the fifth, and that was more than enough for Seattle.

The Twins are averaging 3.1 runs per game in a 3-16 stretch after going two solid months as one of the highest-scoring offenses in the American League.

"Obviously, it's not where we want to be this time of year," second baseman Jamey Carroll said. "It feels like we've taken a step backwards."

Starting pitching has been the team's biggest problem all year, but the bats helped compensate from early June through early August. This is reminiscent of the beginning of the season, when the offense repeatedly stumbled during a 10-26 start.

"[The two stretches] remind me a lot of each other," Willingham said. "How we lose is irrelevant to me, just the fact we're losing."

The Mariners have scored the fewest runs of any AL club (512), yet they have won seven consecutive games against the Twins dating to May 5. During that streak, Seattle has outscored Minnesota 31-10.

One night after Felix Hernandez blanked them 1-0, the Twins couldn't manage an earned run off Iwakuma (5-3) for the second time in two weeks.

"I think [Iwakuma] was effectively wild," Carroll said. "He couldn't really throw his fastball over, so he was using a lot of his offspeed stuff, throwing his split more, and we just couldn't do anything with it."

Carroll had the lone hit off Iwakuma -- a one-out single in the fifth inning. He and Pedro Florimon drew walks to start the third inning, and Mariners catcher Miguel Olivo added a passed ball, but the Twins only turned those gifts into one run, on a sacrifice fly by Ben Revere.

Mauer, who finished 0-for-4, took a called third strike to end that inning.

The Twins mounted one last gasp, as Ryan Doumit delivered a two-out RBI double in the ninth inning, and Trevor Plouffe walked against Mariners closer Tom Wilhelmsen, bringing Carroll to the plate representing the tying run. But Carroll lined out to right field, ending the game.

"You usually see one or two guys go into a little bit of a funk, but right now we're inconsistent pretty much up and down the lineup," Gardenhire said. "We're trying to figure out what's going on; it's not from lack of work. They work their tails off, but right now, nothing's clicking. If it's not one thing, it's another right now."